| transcription factors | Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process. (12 Dec 1998) |
|---|---|
| transcription factors, tfii | The so-called general transcription factors that bind to RNA polymerase II and that are required to initiate transcription. They include tfiia, tfiib, tfiid, tfiie, tfiif, tfiih, tfii-I, and tfiij. In vivo they apparently bind in an ordered multi-step process and/or may form a large preinitiation complex called RNA polymerase II holoenzyme. (12 Dec 1998) |
| transcription factors, tfiii | Factors that bind to RNA polymerase III and aid in transcription. They include the assembly factors tfiiia and tfiiic and the initiation factor tfiiib. All combine to form a preinitiation complex at the promotor that directs the binding of RNA polymerase III. (12 Dec 1998) |
| early-phase response | Prompt onset of symptoms following an antigenic stimulus. (05 Mar 2000) |
| B-cell differentiation/growth factors | Various substances, usually obtained from the supernatant of T-cell cultures, such as interleukin 4, 5, and 6. These substances are necessary for B-cell growth, maturation, and differentiation into plasma cells or B memory cells. (05 Mar 2000) |
| growth factors | Proteins involved in cell differentiation and growth.Growth factors are essential to the normal cell cycle, and are thus vital elements in the life of animals from conception to death. Among other things, they mediate foetal development, play a role in maintenance and repair of tissues, stimulate production of blood cells, and, gone awry, participate in cancerous processes. (05 Mar 2000) |
| haematopoietic cell growth factors | These growth factors comprise a family of haematopoietic regulators with biological specificities defined by their ability to support proliferation and differentiation of blood cells of different lineages. Erythropoietin and the colony-stimulating factors belong to this family. Some of these factors have been studied and used in the treatment of chemotherapy-induced neutropenia, myelodysplastic syndromes, and bone marrow failure syndromes. (12 Dec 1998) |
| stem cell growth factors | <growth factor> Compounds, usually proteins, that make stem cells grow faster. (26 Mar 1998) |
| nerve growth factors | Factors which enhance the growth potentialities of sensory and sympathetic nerve cells. (12 Dec 1998) |
| insulin-like growth factors | Peptides whose formation is stimulated by growth hormone. These peptides bring about peripheral tissue effects of that hormone and have high (about 70%) homology to human insulin. Synonym: somatomedins. (05 Mar 2000) |
| transforming growth factors | <chemical> Hormonally active polypeptides that can induce the transformed phenotype when added to normal, non-transformed cells. They have been found in culture fluids from retrovirally transformed cells and in tumour-derived cells as well as in non-neoplastic sources. Their transforming activities are due to the simultaneous action of two otherwise unrelated factors, transforming growth factor alpha and transforming growth factor beta. Chemical name: Animal growth regulators, transforming growth factors (12 Dec 1998) |
| endothelial growth factors | These growth factors are soluble mitogens secreted by a variety of organs. The factors are a mixture of two single chain polypeptides which have affinity to heparin. Their molecular weight are organ and species dependent. They have mitogenic and chemotactic effects and can stimulate endothelial cells to grow and synthesise DNA. The factors are related to both the basic and acidic fibroblast growth factors but have different amino acid sequences. (12 Dec 1998) |
| reverse transcription | <molecular biology> The process of copying information found in RNA into DNA. (09 Oct 1997) |
| transcription | <molecular biology> Synthesis of RNA by RNA polymerases using a DNA template. (18 Nov 1997) |
| transcription factor | <molecular biology> Protein required for recognition by RNA polymerases of specific stimulatory sequences in eukaryotic genes. Several are known that activate transcription by RNA polymerase II when bound to upstream promoters. Transcription of the 5S RNA gene in Xenopus by RNA polymerase III is dependent on a 40 kD protein TFIIIA that binds to a regulatory site in the centre of the gene and was the first protein found to exhibit the metal binding domains known as zinc fingers. (17 Mar 1998) |