{PS00779; GLYCO_HORMONE_ALPHA_1} {PS00780; GLYCO_HORMONE_ALPHA_2} {BEGIN} ************************************************ * Glycoprotein hormones alpha chain signatures * ************************************************ Glycoprotein hormones [1,2] (or gonadotropins) are a family of proteins which include the mammalian hormones follitropin (FSH), lutropin (LSH), thyrotropin (TSH) and chorionic gonadotropin (CG), as well as at least two forms of fish gonadotropins. All these hormones consist of two glycosylated chains (alpha and beta). In mammalian gonadotropins, the alpha chain is identical in the four types of hormones but the beta chains, while homologous, are different. The alpha chains are highly conserved proteins of about 100 amino acid residues which contain ten conserved cysteines all involved in disulfide bonds [3], as shown in the following schematic representation. +---------------------------+ +----------+| +-------------|--+ | **||*** | | | xxxxCxCxxxxxxCxCCxxxxxxxxxxxxxCCxxxxxxxxxxCxCxxCx | | | *|****** +------|-----------------+ | | | +----------------------------+ 'C': conserved cysteine involved in a disulfide bond. '*': position of the patterns. We have developed two patterns for these hormones. Each of them contains three of the conserved cysteines. -Consensus pattern: C-x-G-C-C-[FY]-S-R-A-Y-P-T-P [The three 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. -Consensus pattern: N-H-T-x-C-x-C-x-T-C-x(2)-H-K [The three 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. -Expert(s) to contact by email: Lapthorn A. adrian@chem.gla.ac.uk -Last update: March 1995 / Text revised. [ 1] Pierce J.G., Parsons T.F. Annu. Rev. Biochem. 50:465-495(1981). [ 2] Stockell Hartree A., Renwick A.G.C. Biochem. J. 287:665-679(1992). [ 3] Lapthorn A.J., Harris D.C., Littlejohn A., Lustbader J.W., Canfield R.E., Machin K.J., Morgan F.J., Isaacs N.W. Nature 369:455-461(1994). {END}