Mixture of proteolytic enzymes from Streptomyces griseus. At least four enzymes are present, including trypsin and chymotrypsin-like proteases.
Haploid nucleus resulting from meiosis. In animals the female pronucleus is the nucleus of the ovum before fusion with the male pronucleus. The male pronucleus is the sperm ...
(= Factor P)
Component of the alternative pathway for complement activation: complexes with C3b and stabilizes the alternative pathway C3 convertase (C3bBbP) that cleaves C3. ...
The genome of a lysogenic bacteriophage when it is integrated into the chromosome of the host bacterium. The prophage is replicated as part of the host chromosome.
Classical term for the first phase of mitosis or of one of the divisions of meiosis. During this phase the chromosomes condense and become visible.
Preventative action that will, for example, prevent infection; thus, vaccination is a prophylactic treatment.
Used as a fluorescent stain for DNA and also for detecting dead cells which are permeable and therefore stain.
Genus of bacteria that will ferment glucose to propionic acid or acetic acid.
Small, colourless plastidprecursor, capable of division. It can develop into a chloroplast or other form of plastid, and has little internal structure. Found in cambial and ...
Potent adrenergic antagonist acting at b 1 and b f573 sf 2 adrenergic receptors.
Searchable dictionary of conserved protein domains. Useful in inferring likely function of novel proteins.
Raspberry-shaped ribonucleoprotein particle (19S) composed of small cytoplasmic RNA (15%) and heat-shock proteins, thought to be involved in post-transcriptional repression of ...
Drosophila gene, product of which is asymmetrically distributed in the division of neural stem cells (neuroblasts) and is not present in one daughter (pluripotent neuroblast) ...
Proposed stage in the development of spherosomes in plant cells. There is an accumulation of lipid in the prospherosome that is mobilized at a later stage.
Unstable prostaglandin released by mast cells and endothelium, a potent inhibitor of platelet aggregation; also causes vasodilation and increased vascular ...
Group of compounds derived from arachidonic acid by the action of cyclo-oxygenase that produces cyclic endoperoxides (PGG2 and PGH2) that can give rise to prostacyclin or ...
Collective term for prostaglandins, prostacyclins and thromboxanes: slightly narrower than eicosanoids.
A tightly bound non-polypeptide structure required for the activity of an enzyme or other protein, eg. the haem of haemoglobin.
Highly basic (arginine-rich) protein that replaces histone in sperm heads, enabling DNA to pack in an extremely compacted form, eg. clupein, iridin (4 kD). See also transition ...
See also peptidase. The term is normally reserved for endopeptidases that have very broad specificity and will cleave most proteins into small fragments. These are usually the ...
Specific inhibitor of urokinase, thrombin and plasmin. Reported to influence neurite outgrowth by regulating the degree of proteolytic activity and thereby preventing excess ...
(= PAR1, 2, 3)
PAR1 is the human thrombin receptor, PAR2 is a possible trypsin receptor and PAR3 is similar to PAR1. All are G-protein-coupled receptors activated by cleavage ...
Family of cathelin-associated antimicrobial peptides found in mammalian leucocytes. Will kill a range of bacteria including Gram positives and are active against multidrug ...
A linear polymer of amino acids joined by peptide bonds in a specific sequence.
Protein obtained from Staphylococcus aureus that binds immunoglobulin molecules without interfering with their binding to antigen. Widely used in purification of ...
Cell surface protein of Group B streptococci that, like protein A, will bind Fc region of immunoglobulin - but preferentially IgA.
Vitamin K-dependent glycoprotein (62 kD) that is the zymogen of a serine endopeptidase (activated protein C; EC 126.96.36.199) found in plasma. Activated protein C in combination ...
Normally means the use of recombinant DNA technology to produce proteins with desired modifications in the primary sequence. See site-specific mutagenesis.
Protein from Group C Streptococci that binds the Fc portion of IgG; less species-specific than protein A.
Enzyme catalysing transfer of phosphate from ATP to hydroxyl side chains on proteins, causing changes in function. Most phosphate on proteins of animal cells is on serine ...
protein kinase C
Family of protein serine/threonine kinases activated by phospholipids that play an important part in intracellular signalling. The classical PKCs ( a, b1, b2, g) are also calcium ...
protein kinase IV
A calcium/calmodulin-dependent protein kinase (53 kD) found in brain, T-cells and postmeiotic male germ cells. Present in nucleus where it phosphorylates and activates CREB ...
protein kinase N
(= PKN; PRK1)
Serine/threonine kinase (100 kD) probably regulated by rho-dependent phosphorylation. Kinase activity resides in the C-terminal region (which has high homology ...
Single chain glycoprotein (69 kD) that promotes binding of protein C to platelets; a vitamin K-dependent cofactor.
protein tyrosine phosphatase
A phosphatase that specifically cleaves the phosphate from a tyrosine residue in a protein - thus reversing the action of a tyrosine kinase. Examples include CD45, shp, dep, ...
Major protein (43 kD) of barley endosperm, structurally similar to a serpin.
The major glycoprotein of peripheral nerve myelin, an integral transmembrane protein (28 kD), synthesized by Schwann cells.
Membrane-bounded droplets supposed to have been formed in ‘primaeval soup’ as an early stages in the evolution of cells.
Form of plastid adapted as a protein storage organelle; the protein may be crystalline.
A high molecular weight complex of protein and polysaccharide, characteristic of structural tissues of vertebrates, such as bone and cartilage, but also present on cell ...
A proteoglycan containing as its glycosaminoglycan heparan sulphate whose constituent N-acetyl glucosamine is often sulphated. Hence highly negatively charged. Syndecan is ...
Obsolete term for hydrophobic integral membrane proteins.
Highly conserved membrane protein (30 kD) in myelin. Cellular function obscure but mutations lethal eg. jimpy mouse and Pelizaeus-Merzbacher disease of man.
Cleavage of proteins by proteases. Limited proteolysis occurs where proteins are functionally modified (activated in the case of zymogens) by highly specific proteases.
Protein equivalent of the genome: the next great challenge!
The 20S proteosome has 28 protein subunits arranged as an (a1 - a 7, b1 - b 7) 2 complex in four stacked rings. The interior of the complex has the active sites. The b -type ...
(1) Genus of highly motile Gram negative bacteria. They are found largely in soil but are also found in the intestine of humans. They are opportunistic pathogens; P. mirabilis ...
Independent gametophyte phase of horsetail or fern.
Inactive precursor of thrombin, found in blood plasma.
The kingdom of eukaryotic unicellular organisms. It includes the Protozoa, unicellular eukaryotic algae and some fungi (myxomycetes, acrasiales and oomycetes).
The normal, cellular equivalent of an oncogene; thus usually a gene involved in the signalling or regulation of cell growth. In general, cellular proto-oncogenes are prefixed ...
Precursor of chlorophyll, found in proplastids and etioplasts. Lacks the phytol side chain of chlorophyll.
One way of viewing microtubule structure is to consider it to be built of (usually) 13 protofilaments arranged in parallel.
An immature form of lignin that can be extracted from the plant cell wall with ethanol or dioxane.
Primary lysosome that has not been involved in fusion with another vesicle or in digestive activity.
Subunits from which a larger structure is built. Thus the tubulin heterodimer is the protomer for microtubule assembly, G-actin the protomer for F-actin. Because it avoids ...
An ion pump that actively transports hydrogen ions across lipid bilayers in exchange for ATP. Major groups are the F-type ATPases, that run in reverse to ...
Ionophore that carries protons. Many uncoupling agents are protonophores.
A bacterial cell deprived of its cell wall, for example by growth in an isotonic medium in the presence of antibiotics that block synthesis of the wall peptidoglycan. ...
Porphyrin ring structure lacking metal ions. The most abundant is protoporphyrin IX, the immediate precursor of haem.
Invertebrate phylum in which the mouth forms from the embryonic blastopore. Major protostome phyla are Annelida, Mollusca and Arthropoda. See deuterostome.
A very diverse group comprising some 50,000 eukaryotic organisms that consist of one cell. Because most of them are motile and heterotrophic, the Protozoa were originally ...
In plant cells provacuoles are budded directly from the rough endoplasmic reticulum and fuse with other provacuoles to form vacuoles. Since vacuoles may contain hydrolytic ...
The genome of a virus when it is integrated into the host cell DNA. In the case of the retroviruses, their RNA genome has first to be transcribed to DNA by reverse ...
Proprietary name for a serotonin uptake inhibitor used extensively as an antidepressant.
Prozone phenomena occur in immunological reactions when the concentrations of antibody or other active immune agent are so high that the optimum concentration for maximal ...
(= condensing vacuole)
Stage in the development of a mature secretory vesicle (zymogen granule).
PrPc is a normal protein anchored to the outer surface of neurons and, to a lesser extent, the surfaces of other cells, including lymphocytes. The prion thought to be responsible ...
(= prostate specific antigen)
Antigen in serum that seems to be a relatively reliable marker for prostatic hyperplasia/carcinoma. Antigen is a serine endopeptidase related to ...
Family of postsynaptic density proteins containing PDZ domains and apparently responsible for the clustering of receptors. The PSD-95 protein is responsible for the clustering ...
Non-functional DNA sequences that are very similar to the sequences of known genes. Examples are those found in the b -like globin gene cluster. Some probably result from gene ...
Genus of Gram negative bacteria. They are rod-shaped and motile, possessing one or more polar flagella. Several species produce characteristic water-soluble fluorescent ...
Blunt-ended projection from a cell - usually applied to cells that have an amoeboid pattern of movement.
Class of natural compounds (diterpene-pentose glycosides) isolated from the soft coral Pseudopterogorgonia elisabethae, and that interfere with arachidonic acid metabolism. ...
pseudospatial gradient sensing
Mechanism for sensing a gradient of a diffusible chemical in which the cell sends protrusions out at random; up-gradient protrusions are stabilized by positive feedback (because ...
Unusual nucleotide found in some tRNA: glycosidic bond is associated with position 5\' of uracil, not position 1\'.
P-selectin glycoprotein ligand; expressed on neutrophils, monocytes and most lymphocytes. An extended mucin-like transmembrane glycoprotein expressed as a homodimer. ...
Drugs capable of forming photoadducts with nucleic acids if ultraviolet-irradiated.
Chronic inflammatory skin disease characterized by epidermal hyperplasia. Lesions may be limited or widespread and in the latter case the disease can be life-threatening. Unlike ...
(= phosphatase and tensin homolog deleted on chromosome ten; MMAC1/PTEN; TEP-1)
A protein tyrosine phosphatase with homology to tensin, is a tumour-suppressor gene on ...
Nitrogen-containing compound composed of two six-membered rings (pyrazine and pyrimidine rings). Structural component of folic acid and riboflavin ...
Division of the plant kingdom that includes ferns, horsetails and clubmosses.
Cell line from Potorous tridactylis (potoroo or kangaroo rat) kidney. Often used in studies on mitosis because there are only a few large chromosomes and the cells remain ...
Drooping of the upper eyelid for any one of a number of causes. May be a result of damage to the third cranial nerve, to myasthenia gravis, to Horner&’s syndrome or simply be ...
(= protein tyrosine phosphatase)
A phosphatasethat reverses the effect of a tyrosine kinase.
Common name for a -amylase found in saliva.
Purine rich sequence recognized by the product of the Sp-1 oncogene.
(= poly-unsaturated fatty acid)
Increasing the ratio of unsaturated to saturated fatty acids can alter the behaviour of cells, probably by altering physical characteristics of ...
Expanded areas of a polytene chromosome. At these areas the chromatin becomes less condensed and the fibres unwind, though they remain continuous with the fibres in the ...
An experimental protocol used to determine cellular pathways, such as precursor-product relationships. A sample (organism, cell or cellular organelle), is exposed for a ...
A method used for high-resolution electrophoretic separation of very large (megabase) fragments of DNA. Electric fields 100° apart (the angle may vary) are applied to the ...
The checkerboard (matrix) method used to determine the types of zygotes produced by fusion of gametes from parents of defined genotype.
A heterocyclic compound with a fused pyrimidine/imidazole ring. Planar and aromatic in character. The parent compound for the purine bases of nucleic acids.
A class of neuron in the cerebellum; the only neurons that convey signals away from the cerebellum.
Specialized cardiac muscle cells that conduct electrical impulses through the heart and are involved in regulating the beat.
An antibiotic that acts as an aminoacyl tRNA analogue. Binds to the A-site on the ribosome, forms a peptide linkage with the growing chain and then causes premature ...
Plasma membrane of Halobacterium and Halococcus, that contains a protein-bound carotenoid pigment that absorbs light and uses the energy to translocate protons from the cytoplasm ...
Heparin-binding protein (20 kD) released by chick neural retina cells in culture.
A dibasic amine associated with putrifying tissue. Associates strongly with DNA. Has been suggested as a growth factor for mammalian cells in culture. Metabolic precursor of the ...
(= polyvinyl pyrrolidone)
Water-soluble white compound that when dissolved make a very viscous solution.
Invasion of bloodstream by pyogenic organisms.
Contraction of nuclear contents to a deep-staining irregular mass; sign of cell death.
Bacteriocins produced by bacteria of the genus Pseudomonas.
Blue-green phenazine pigment produced by Pseudomonas aeruginosa ; has antibiotic properties.
Causing the formation of pus, a thick yellow or greenish liquid formed at a site of infection, and that contains dead leucocytes, bacteria and tissue debris.
Sugar structure in which the carbonyl carbon is condensed with a hydroxyl group (ie. in a hemi-acetal link), forming a ring of five carbons and one oxygen. Most hexoses exist in ...
Small body found within some chloroplasts, that may contain protein. In green algae may be involved in starch synthesis.
Toxic hydrocarbon, originally from chrysanthemum flowers, that now forms the basis for a wide range of ‘natural’ synthetic pyrethroid insecticides.
The coenzyme derivative of vitamin B6. Forms Schiff\'s bases of substrate amino acids during catalysis of transamination, decarboxylation and racemisation reactions.
(= 1,3 diazine)
A heterocyclic 6-membered ring, planar and aromatic in character. The parent compound of the pyrimidine bases of nucleic acid.
Substance or agent that produces fever. The major endogenous pyrogen in mammals is probably interleukin-1.
A heterocyclic ring structure, found in many important biological pigments and structures that involve an activated metal ion, eg. chlorphyll, haem.
(= 2-oxopropanoate; CH3COCOO-)
Important intermediate in many metabolic pathways, particularly of glucose metabolism and the synthesis of many amino acids.
An enzyme that catalyses the formation of oxaloacetate from pyruvate, CO2 and ATP in gluconeogenesis.
A complex multienzyme system that catalyses the conversion of (pyruvate + CoA + NAD+) to (acetyl CoA + CO2 + NAD).
See banding patterns and quinacrine.
An RNA virus that infects E. coli. Genome circular, single-stranded and acts both as template for replication of a complementary strand and as messenger RNA.
Glutamine-rich sequence found in some transcription factors.
Converts amylose to amylopectin.
Typhus-like illness caused by rickettsia, Coxiella burneti.Mainly a disease of domestic animals but can be caught by man.
A class of voltage-sensitive calcium channels. May be identical or very similar to P-type channels. Inhibited by neurotransmitters that act through G-protein-coupled receptors, ...
Ratio of the velocity of reaction at one temperature and that at a temperature 10°C lower. Usually around 2 for biological reactions.
QH2-cytochrome c reductase
Membrane-bound complex in the mitochondrial inner membrane, responsible for electron transfer from reduced coenzyme Q to cytochrome c. Contains cytochromes b and c1, and ...
Quail homologues of MyoD, myogenin and myf-5, respectively.
(= quantitative structure-activity relationship)
Relationship between the structure of a compound and its activity in binding or inhibiting something, based upon computed ...
A fluorescent calcium indicator. Resembles the chelator EGTA in ability to bind calcium much more tightly than magnesium. Binding of calcium causes large changes in ultraviolet ...
A fluorescent dye that intercalates into DNA helices. Chromosomes stained with quinacrine show typical banding patterns of fluorescence at specific locations, Q bands, that can ...
quinate: NAD oxidoreductase
A plant enzyme converting hydroquinic acid (a derivative of the shikimate pathway) to quinic acid. The enzyme is activated by a calcium- and calmodulin-dependent phosphorylation.
An alkaloid isolated from cinchona bark. Used as an antimalarial. It is believed to act by raising the pH of endocytotic vesicles and inhibiting internal membrane fusion ...
Aromatic dicarbonyl compound derived from a dihydroxy aromatic compound. Ubiquinone (coenzyme Q) is a dimethoxy-dicarbonyl derivative of benzene involved in electron transport. ...
Enzymes that reduce quinones to phenols usually using NADH or NADPH as a source of reductant.
An agonist of the Q-type excitatory amino acid receptor. See kainate.
Open-channel blocker at nicotinic acetylcholine receptors; a quaternary ammonium derivative of the local anaesthetic Lidocaine. In mouse muscle AChR it blocks by interacting ...
A protein structure, visible by optical microscopy, found in various bacteria, probably related to plasmid presence. Found both in free-living pseudomonads and in various ...
A single-stranded loop section of DNA formed by the association of a section of ssRNA with the other strand of the DNA in this region whereby one DNA strand is displaced as the ...
(= R factor; drug resistance factor)
A plasmid that confers resistance to one or more antibiotics or other poisonous compounds in a bacterium.
A class of neuronal voltage-sensitive calcium channels that are unaffected by dihydropyridines, phenylalkylamines and conotoxins. Thought to carry much of the current, ...
Bacteriophage with RNA genome that codes for the enzyme RNA synthetase and for the coat protein, a protein to which the RNA is attached and that is involved in attachment to ...
See G-protein-coupled receptors.
(1) One of the three main groups of ras-like genes specifying small GTP-binding proteins (the others are ras and rho). Rab proteins are involved in vesicular traffic and seem to ...
Rabaptin-5 (117 kD) interacts with rab5-GTP and is essential for rab-mediated endosomal fusion. Both ends of rabaptin have coiled-coil domains characteristic of vesicular ...
Species of the Rhabdoviridae that causes rabies in humans. The virus infects the cells in the brain, causing a fatal encephalomyelitis. It is found all over the world, but ...
Protein (50 kD) that interacts with rab3A and rab3D but not with other small GTPases.
Receptor (704 amino acid residues) for the small GTP-binding protein rab3A that is implicated in regulated secretion, particularly of neurotransmitters. The N terminal region ...
Small GTP-binding protein involved in regulating actin cytoskeleton - the activated form of rac seems to induce membrane ruffling (whereas rho acts on stress fibres). Rac may ...
See rapid amplification of DNA ends.
A mixture containing equimolar amounts of two enantiomers (D- and L-forms) of a chiral molecule.
To do with rickets, a disease caused by Vitamin D deficiency.
(= receptors for activated C Kinase)
Proteins, usually anchored to specific areas of the cell, which selectively bind activated protein kinase C and thus control the regions of ...
(1) Abbreviation for radian.
(2) Unit of radiation 1rad = 0.01Gy.
(3) rad1 is a Schizosaccharomyces pombe checkpoint control gene important in both DNA damage-dependent and ...
(= rad 50, 51, 52, 54, 55, 57, 59; MRE11, XRS2)
Yeast proteins coded by genes originally identified as being particularly sensitive to X-rays. Required for spontaneous and ...
Conserved protein that is important in nucleotide excision repair. N-terminal domain has similarity with ubiquitin and links rad23 to the proteosome. Binds to rad14 and TFIIH ...
radial glial cell
A type of glial cell, organized as parallel fibres joining the inner and outer surfaces of the developing cortex. They are thought to play a role in neuronal guidance in ...
The structure that links the outer microtubule doublet of the ciliary axoneme with the sheath that surrounds the central pair of microtubules. The spokes are arranged ...
The technique of inactivating proteins in freeze dried (lyophilised) preparations using high energy particles (eg. electrons). One high-energy particle can apparently inactivate ...
Any system for testing antigen-antibody reactions in which use is made of radioactive labelling of antigen or antibody to detect the extent of the reaction.
Form of a chemical element with unstable neutron number, so that it undergoes spontaneous nuclear disintegration. Major use in biology is to trace the fate of atoms or molecules ...
Subclass of the Sarcodina. Marine protozoans with silicaceous exoskeleton and radiating filopodia.
Barbed-end capping actin-modulating protein (82 kD) found in adherens junctions and in the cleavage furrow of many cells.
1. Gene for raf; see miloncogene.
2. Serine/threonine protein kinase implicated in signal-reponse transduction pathways involving tyrosine-kinases. Apparently raf-1 is ...
A non-reducing trisaccharide found in sugar beet and many seeds, consisting of the disaccharide sucrose bearing a D-galactosyl residue linked a (1-6) to its ...
Raji cell binding test
A test for the detection of soluble IgG-antigen complexes. Raji cells are a line of EBV-transformed lymphocytes with surface Fc receptors. Complexes are detected by their ...
Cell line that grows in suspension derived from patient with Burkitt&’s lymphoma.
Tyrosine kinase (54 kD) found in nucleus. Has N-terminal SH2 and SH3 domains and has similarities with src. Binds to Rb protein and leads to growth suppression.
Oncogene related to ras. Protein product is a ras-like GTPase.
Method for measuring the Raman spectrum, the plot of Raman scattering of light that produces weak radiation at frequencies not present in the incident radiation. The spectrum is ...
(= receptor activity modifying proteins)
RAMPs are type I transmembrane proteins that associate with and regulate properties of receptors. If the calcitonin receptor-like ...
Small G-protein (GTPase) required, together with importins a and b and pp15, for protein transport into the nucleus. The only known nucleotide exchange factor for ran is ...
A term originally invented by polymer chemists to describe a disordered tangle of a linear polymer chain with curved sections. In DNA parlance the random coil refers to the ...
Method of labelling a DNA probe for use in hybridization. Double-stranded DNA is denatured to form a single stranded template. Random oligonucleotide primers (usually ...
A description of the path followed by a cell or particle when there is no bias in movement. The direction of movement at any instant is not influenced by the direction of travel ...
(= regulated upon activation normal T-expressed and secreted)
Cytokine of the C-C subfamily, produced by T-cells, and chemotactic for monocytes, memory T-cells and eosinophils. ...
Oncogene related to ras.
(1) Small GTP-binding protein which seems to antagonise ras activity. Has antimitogenic activity, seems to be involved in NGF-induced neuronal differentiation and T-cell ...
Large subunit of the transcription initiation factor (TFIIF).
Immunosuppressive macrolide antibiotic with structural similarity to FK 506; inhibits T- and B-cell proliferation but at a much later stage than FK 506, despite binding to the ...
Variation of the polymerase chain reaction used to identify differentially expressed genes. mRNA from two different tissue samples is reverse transcribed, then amplified using ...
Rod-shaped particle found in bacterial cell near DNA-rich region.
rapid amplification of DNA ends
(= RACE; 3&’ RACE; 5&’ RACE)
Techniques, based on the polymerase chain reaction, for amplifying either the 5&’ end (5&’ RACE) or 3&’ end (3&’ RACE) of a cDNA ...
One of a family of oncogenes, first identified as transforming genes of Harvey and Kirsten murine sarcoma viruses. (‘ras’ from rat sarcoma because Harvey virus, though a ...
Family of small G-proteins (rac, rab, ran, rad, rho, gem, kir, ric, rin, rit, Ypt). The rab subfamily is required for membrane traffic in eukaryotic cells, ral has been ...
ratio-imaging fluorescence microscopy
A method of measurement of intracellular pH or intracellular calcium levels, using a fluorescent probe molecule (see fura-2), in which the two different excitation wavelengths ...
RAW 264 cells
Murine monocyte/macrophage line derived from ascitic tumour induced with Abelson leukaemai virus.
Tumour suppressor gene encoding a nuclear protein that, if inactivated, enormously raises the chances of development of cancer, classically retinoblastoma, but also other ...
Red blood cell or erythrocyte
Rat basophilic leukaemia cell line: shows wide variation but can be used as a model for basophils.
DNA that codes for ribosomal RNA.
The site in the chloroplast that receives the energy trapped by chlorophyll and accessory pigments, and initiates the electron transfer process.
reactive oxygen species
Oxygen-containing radical or reactive ions such as superoxide, singlet oxygen and hydroxyl radicals, the product of the respiratory burst in phagocytes and responsible for ...
One of the three possible ways of reading a nucleotide sequence. As the genetic code is read in non-overlapping triplets (codons) there are three possible ways of translation ...
Reaginic antibodies; an outmoded term for IgE.
Renaturation of a DNA sample that has been dissociated by heating. In reannealing the two strands that recombine to form a double-stranded molecule are from the same source. ...
Regulator of apoptosis in Drosophila. Has no known homology with vertebrate proteins but reaper-induced apoptosis is blocked by caspase inhibitors and human IAPs. See also ...
Protein (40 kD) product of the rec (recombination) gene, that catalyses the pairing of a single-stranded piece of DNA with its complementary sequence, displacing a loop of ...
The outmoded theory that the stages of development (ontogeny) recapitulated the evolutionary stages through which an organism had passed (phylogeny) ; thus the primitive ...
Protein (140 kD) ; one subunit of nuclease that unwinds double-stranded DNA and fragments the strands sequentially; the other subunit is recC (128 kD)
Cells in the photosynthetic tissues of plants into which the solutes from xylem are pumped.
In general terms, a membrane-bound or membrane-enclosed molecule that binds to, or responds to something more mobile (the ligand), with high specificity. Examples: ...
A phenomenon observed in many cells: following stimulation with a ligand the number of receptors for that ligand on the cell surface diminishes because internalisation exceeds ...
The transmembrane potential difference of a sensory cell. Such cells are not generally excitable, but their response to stimulation is a gradual change in their resting ...
receptor tyrosine kinase
Class of membrane receptors that phosphorylate tyrosine residues. Many play significant roles in development or cell division. Examples: insulin receptor family, c- ros ...
Endocytosis of molecules by means of a specific receptor protein that normally resides in a coated pit, but may enter this structure after complex formation occurs. The ...
receptors for activated C Kinase
Proteins, usually anchored to specific areas of the cell, which selectively bind activated protein kinase C and thus control the regions of the cell on which it acts. ...
An allele or mutation that is only expressed phenotypically when it is present in the homozygous form. In the heterozygote it is obscured by dominant alleles.
Region of cytoplasm in the rear third of a moving amoeba where endoplasm is recruited from ectoplasm.
An electrical synapseat which current flow can only occur in one direction.
red blood cell
Cell specialized for oxygen transport, having a high concentration of haemoglobin in the cytoplasm (and little else). Biconcave, anucleate discs, ca 7 m m ...
red drop effect
Experimental observation that the photosynthetic efficiency of monochromatic light is greatly reduced above 680nm, even though chlorophyll absorbs well up to 700nm. Led to the ...
Phenomenon in which the sea appears red as a result of massive increase in the population of a dinoflagellate ( Gymnopodium ) ; unfortunately the dinoflagellate contains a ...
The reducing/oxidising power of a system measured by the potential at a hydrogen electrode.
Mouse autosomal recessive mutant, deficient in reelin and with disruption in large areas of the brain. Reelin, a large extracellular protein, is secreted by Cajal-Retzius ...
Protein product (99 kD) of mouse releer gene, an extracellular matrix component produced by pioneer neurons and important in cortical neuronal migration.
Adjective usually used in describing granules within cells that scatter (refract) light. Not to be confused with refractory.
Most commonly used in reference to the interval (typically 1ms) after the passage of an action potential during which an axon is incapable of responding to another. This is ...
Islet cell mitogen, the product of the pancreatic regulating ( reg1 ) gene. Expression of reg1 inversely correlates with cell differentiation and can be modulated by ...
Potent Schwann cell mitogen,a secreted protein of 16 kD. Produced by motor and sensory neurons during development, production possibly regulated by LIF/CNTF.
(=b (= REGa = PA28a; REGb; REGg (Ki antigen) )
Components of the 11S proteosome activator that stimulates peptidase activity and enhance the processing of antigens for ...
Processes of repair or replacement of missing structures.
(= control element)
DNA sequence to which regulatory molecules such as promotors or enhancersbind, thereby altering the expression of the adjacent gene.
Vague term for any class of T-lymphocyte not directly involved in the effector side of immunity, but involved in controlling responses and actions of other cells; especially ...
A situation in which two or more spatially separated genes are regulated in a coordinated fashion by a common regulator molecule.
Usually used of grafts. Any process leading to the destruction or detachment of a graft or other specified structure.
Protein that acts as a transcription factor. It was first identified as the oncogene product of the lethal, avian retrovirus Rev-T. It has a N-terminal region of 300 amino ...
An oncogene, identified in avian endotheliosis, encoding a nuclear gene.
Time taken for a system to return to the resting or ground state or a new equilibrium state following perturbation. Often used in context of receptor systems that have a ...
Polypeptide hormone produced by corpus luteum and found in the blood of pregnant animals. Acts, as its name suggests, to cause muscle relaxation during parturition. Human ...
Complex multi-subunit structure forming at the plasmid origin of replication which nicks supercoiled DNA.
A component of the specialized transport system involved in the transport of cobalamin (vitamin B12) across the wall of the intestine. Dissociates the complex between cobalamin ...
Associated with the kidney.
The conversion of denatured protein or DNA to its native configuration. This is rare for proteins. However, if DNA is denatured by heating, the two strands separate and if the ...
An acid protease released from the walls of afferent arterioles in the kidney when blood flow is reduced, plasma sodium levels drop, or plasma volume diminishes. Catalyses ...
Class III viruses, with a segmented double-stranded RNA genome; there are about 8-10 segments each coding for a different polypeptide and only one strand of the RNA (minus ...
Class of enzymes involved in DNA repair. It includes endonucleases that recognize a site of damage or an incorrect base pairing and cut it out, and exonucleases that remove ...
repellant guiding molecule
Specific molecules that inhibit the activity of growth cones and are thought to be important in establishing axon pathways during nervous system development. See growth cone ...
Damage that occurs to tissue when blood flow is restored after a period of ischaemia. The damage is caused by neutrophils that adhere to the microvasculature and release ...
Nucleotide sequences in DNA that are present in the genome as numerous copies. Originally identified by the value on the Cot curve derived from kinetic studies of DNA ...
Methods in the preparation of specimens for transmission electron microscopy. The specimen (for example, a piece of freeze fractured tissue) is shadowed with metal and coated ...
Technique for testing the genetic characteristics of bacterial colonies. A dilute suspension of bacteria is first spread, in a petri dish, on agar containing a medium expected ...
Generic (and rather unhelpful) term for an enzyme that duplicates a polynucleotide sequence (either RNA or DNA). The term is more usefully restricted to the enzyme involved in ...
Copying, but usually the production of daughter strands of nucleic acid from the parental template.
replication factor A
(= replication protein A; RPA)
Protein that associates, together with the PIK3-kinase-like kinase (ATM), at sites where homologous regions of DNA interact during meiotic ...
Point at which DNA strands are separated in preparation for replication. Replication forks thus move along the DNA as replication proceeds.
Intermediate stage(s) in the replication of a RNA virus; a copy of the original RNA strand, or of a single-strand copy of the first replicative intermediate. Essentially an ...
Tandem regions of replication in a chromosome, each about 30 m m long, derived from an origin of replication. By definition a replicon must contain an origin of replication.
Complex of proteins involved in the replication (elongation) of DNA that moves along as the new complementary strand is synthesized. On this basis a minimum content would be DNA ...