Human pregnancy-specific glycoproteins (PSGs) are a family of proteins synthesized in large quantities by the placental trophoblast and released into the maternal circulation during pregnancy. Molecular cloning and analysis of several PSG genes has shown that PSG forms a subset of the carcinoembryonic antigen (CEA) gene family that belongs to the immunoglobulin superfamily genes. Members of the CEA family consist of a single N domain structurally similar to the immunoglobulin variable domain, followed by a variable number of constant immunoglobulin-like A and/or B domains. Most PSGs have the Argglyasp (RGD) motif in the N-terminal domain. It has been shown to act as an adhesion recognition signal for some integrins.[1]
Zoubir F, Khan WN, Hammarström S (May 1990). "Carcinoembryonic antigen gene family members in submandibular salivary gland: demonstration of pregnancy-specific glycoproteins by cDNA cloning". Biochemical and Biophysical Research Communications. 169 (1): 203–16. doi:10.1016/0006-291X(90)91455-2. PMID2350345.
Streydio C, Lacka K, Swillens S, Vassart G (Jul 1988). "The human pregnancy-specific beta 1-glycoprotein (PS beta G) and the carcinoembryonic antigen (CEA)-related proteins are members of the same multigene family". Biochemical and Biophysical Research Communications. 154 (1): 130–7. doi:10.1016/0006-291X(88)90660-2. PMID3260773.