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- *****************************
- * TGF-beta family signature *
- *****************************
-
- Transforming growth factor-beta (TGF-beta) [1] is a multifunctional peptide
- that controls proliferation, differentiation and other functions in many cell
- types. TGF-beta-1 is a peptide of 112 amino acid residues derived by
- proteolytic cleavage from the C-terminal of a precursor protein. A number of
- proteins are known to be related to TGF-beta-1 [1,2]. They are listed below.
-
- - At least four other forms of TGF-beta have been found, they are known as
- TGF-beta-2, -3, -4 and -5.
- - Mullerian inhibitory substance (MIS), produced by the testis, which is
- responsible for the regression of the Mullerian ducts in the male embryo.
- - Inhibins, which inhibit the secretion of follitropin by the pituitary
- gland, and activins which have the reverse action. Inhibins are heterodimer
- of an alpha chain and a beta-A or a beta-B chain; activins are either
- homodimers of beta-A chains or heterodimers of a beta-A and a beta-B chain.
- All three chains are related to TGF-beta.
- - Bone morphogenetic proteins [3] BMP-2, BMP-3 (osteogenin), BMP-4 (BMP-2B),
- BMP-5, BMP-6 (VGR-1), BMP-7 (OP-1) and BMP-8 (OP-2) which induce cartilage
- and bone formation and which are probably involved in the control of the
- production of skeletal structures during development.
- - The embryonic growth factor GDF-1, which may mediate cell differentiation
- events during embryonic development.
- - Mouse protein nodal, which seems essential for mesoderm formation [4].
- - Chicken dorsalin-1 (dsl-1) [5] which may regulate cell differentiation
- within the neural tube.
- - Xenopus vegetal hemisphere protein Vg1, which seems to induce the overlying
- animal pole cells to form mesodermal tissue.
- - Drosophila decapentaplegic protein (DPP-C), which participates in the
- establishment of dorsal-ventral specification.
- - Drosophila protein 60A.
-
- Proteins from the TGF-beta family are only active as homo- or heterodimer;
- the two chains being linked by a single disulfide bond. From X-ray studies of
- TGF-beta-2 [46, it is known that all the other cysteines are involved in
- intrachain disulfide bonds. As shown in the following schematic
- representation, there are four disulfide bonds in the TGF-betas and in inhibin
- beta chains, while the other member of this family lack the first bond.
-
- interchain
- |
- +------------------------------------------|+
- | ******* ||
- xxxxcxxxxxCcxxxxxxxxxxxxxxxxxxCxxCxxxxxxxxxxxxxxxxxxxCCxxxxxxxxxxxxxxxxxxxCxCx
- | | | | | |
- +------+ +--|----------------------------------------+ |
- +------------------------------------------+
-
- 'C': conserved cysteine involved in a disulfide bond.
- '*': position of the pattern.
-
- As a pattern to detect these proteins, we use a region which includes two of
- the conserved cysteines.
-
- -Consensus pattern: [LIVM]-x(2)-P-x(2)-[FY]-x(4)-C-x-G-x-C
- [The two C's are involved in disulfide bonds]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: June 1994 / Text revised.
-
- [ 1] Roberts A.B., Sporn M.B.
- (In) Peptide growth factors and their receptors, Handbook of Experimental
- Pharmacology, Vol. 95, pp419-475, Springer Verlag, Heidelberg, (1990).
- [ 2] Burt D.W.
- Biochem. Biophys. Res. Commun. 184:590-595(1992).
- [ 3] Kingsley D.M.
- Trends Genet. 10:16-21(1994).
- [ 4] Zhou X., Sasaki H., Lowe L., Hogan B.L.M., Kuehn M.R.
- Nature 361:543-547(1993).
- [ 5] Basler K., Edlund T., Jessell T.M., Yamada T.
- Cell 73:687-702(1993).
- [ 6] Daopin S., Piez K.A., Ogawa Y., Davies D.R.
- Science 257:369-373(1992).
-