| hepatocyte growth factor | <growth factor> Polypeptide mitogen originally shown to cause cell division in hepatocytes. In the liver, the main sources of hepatocyte growth factor are nonparenchymal cells. It is now clear that hepatocyte growth factor is a mitogen for a number of cell types and it is found in many cells outside the liver, including platelets. Hepatocyte growth factor is synthesised as a single chain precursor that is proteolytically cleaved to give a heavy chain (70 kD) and a light chain (30 kD) linked by a single disulphide bond. It contains multiple copies of the kringle domain. However, both the single chain precursor and the two chain forms of hepatocyte growth factor are biologically active and hepatocyte growth factor is generally isolated as a mixture of the two forms. Hepatocyte growth factor also alters cell motility and is now known to be identical to scatter factor. Acronym: HGF (18 Nov 1997) |
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| hepatocyte | <pathology> Epithelial cell of liver. Often considered the paradigm for an unspecialised animal cell. Blood is directly exposed to hepatocytes through fenestrated endothelium and hepatocytes have receptors for sub terminal N acetyl galactosamine residues on asialo glycoproteins of plasma. (18 Nov 1997) |
| gibberellin 2beta, 3beta-hydroxylase | <enzyme> Bifunctional enzyme from pumpkin endosperm; catalyses all 3 beta hydroxylations of c19 and c20 gibberillins and all 2 beta hydroxylations of c20 gibberellins; genbank u63650 Registry number: EC 1.14.99.- Synonym: cm3h gene product, ga 2beta, 3beta-hydroxylase (26 Jun 1999) |
| gibberellin 3beta-hydroxylase | <enzyme> Product of le (stem length) gene of pea (pisum sativum) described by mendel; genbank u93210 Registry number: EC 1.14.99.- Synonym: ga4 gene product, le gene product, ga 3beta-hydroxylase (26 Jun 1999) |
| delta5-3beta-hydroxysteroid acyltransferase | <enzyme> Forms esters of palmitate, oleate, linoleate, stearate and myristate with pregnenolone or dehydroepiandrosterone; from rat brain microsomes Registry number: EC 2.3.1.- Synonym: pregnenolone o-acyltransferase, dehydroepiandrosterone o-acyltransferase (26 Jun 1999) |
| 3-dehydroecdysone 3beta-reductase | <enzyme> Converts 3-dehydroecdysone into ecdysone; a 36 kD enzyme from haemolymph of cotton leafworm spodoptera littoralis, involved in ecdysteroid biosynthesis Registry number: EC 1.1.3.- (26 Jun 1999) |
| 5alpha-androstane-3beta-hydroxysteroid dehydrogenase | <enzyme> Converts dihydrotestosterone to 5alpha-androstan-3,17-beta-diol Registry number: EC 1.1.1.- Synonym: 5alpha-ane-3beta-hsdase (26 Jun 1999) |
| nuclear factor 1 | See: CTF. (18 Nov 1997) |
| receptors, cytoplasmic and nuclear | Proteins in the cytoplasm or nucleus that specifically bind signalling molecules and trigger changes which influence the behaviour of cells. The major groups are the steroid hormone receptors, which usually are found in the cytoplasm, and the thyroid hormone receptors, which usually are found in the nucleus. Receptors, unlike enzymes, generally do not catalyze chemical changes in their ligands. (12 Dec 1998) |
| Remak's nuclear division | <cell biology> An unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell without chromosome condensation or spindle formation. Partitioning of daughter chromosomes is haphazard. Observed in some Protozoa. (18 Nov 1997) |
| Pelger-Huet nuclear anomaly | Congenital inhibition of lobulation in the nuclei of neutrophilic leukocytes; most cells present band or bilobulate appearance, and only an occasional cell is trilobed; it is not associated with disease, but may be confused with leukocyte "shift to left"; autosomal dominant inheritance. (05 Mar 2000) |
| ribonucleoproteins, small nuclear | Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm. The u3 snrnp is localised in the nucleolus, where it aligns into base pairs with the 28s rrna precursor in a still unidentified region and functions in pre-rrna processing. The u7 snrnp aligns into base pairs with a conserved sequence in the 3'-end of histone pre-mRNA and is an essential cofactor for the cleavage that creates the mature nonadenylated 3'-end. (12 Dec 1998) |
| RNA, heterogeneous nuclear | Nuclear nonribosomal RNA larger than about 1000 nucleotides, the mass of which is rapidly synthesised and degraded within the cell nucleus. Some heterogeneous nuclear RNA may be a precursor to mRNA. However, the great bulk of total hnrna hybridises with nuclear DNA rather than with mRNA. (12 Dec 1998) |
| RNA, nuclear | RNA molecules found in the nucleus either associated with chromosomes or in the nucleoplasm. (12 Dec 1998) |
| RNA, small nuclear | Short chains of RNA found in the nucleus. Their function is to remove the introns (nontranslated intervening sequences) from mRNA precursors, thereby bringing the two exons (coding segments) together into correct juxtaposition for enzymatic splicing at the correct point. The resulting mRNA is now ready to leave the nucleus. (12 Dec 1998) |