Glycoprotein Hormone Alpha 2 (GPHa2)

GPHA2 is a cystine knot-forming polypeptide and a subunit of the dimeric glycoprotein hormone family.The deduced 129-amino acid precursor protein contains a 23-amino acid signal peptide at its N terminus. The mature 106-amino acid protein has 2 N-glycosylation sites and a calculated molecular mass of 11.7 kD.

GPA2 shares only 35% amino acid identity with GPA1 (CGA); however 9 of 10 cysteines are arranged similarly in the 2 proteins, and GPA2 is expected to fold into a cystine knot like that formed by CGA. PCR analysis detected GPA2 in pituitary, ovary, testis, kidney, and pancreas. Transfection of GPA2 cDNA in human embryonic kidney cells resulted in a secreted protein of about 13 kD.