Identification of a new carcinoembryonic antigen (CEA) family member in human fetal liver--cloning and sequence determination of pregnancy-specific glycoprotein 7.
The carcinoembryonic antigen gene family consists of the CEA- and the Pregnancy-Specific Glycoprotein- (PSG) subfamilies. Human fetal liver express several PSGs. Here we report cloning and sequencing of a new PSG subfamily member, PSG7. It is the fifth type of PSG found in fetal liver. PSG7 has the N-A1-A2-B2-C domain arrangement. Unlike other PSGs the N-terminal of PSG7 is unblocked. PSG7 has a cysteine in the C-terminal domain, which may allow dimerization. Variability analysis according to Wu and Kabat reveals that the region in the N-domain corresponding to complementarity determining region 3 of immunoglobulin is different between PSG subfamily members. Many members, including PSG7, contain the RGD sequence in this region. The CD2 region as well as two other short sequences (in N and A1 domains respectively) also show some variability. The function of PSGs is probably linked to the N-domain and the CDR2- and CD3-like regions are most likely responsible for ligand binding.
Khan
W N
WN
Department of Immunology, University of Umeå, Sweden.
Hammarström
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D002272:Carcinoembryonic Antigen / Q000235:genetics; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics; D008099:Liver / Q000502:physiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D011257:Pregnancy Proteins / Q000235:genetics*; D011268:Pregnancy-Specific beta 1-Glycoproteins; D015183:Restriction Mapping
D002272:Carcinoembryonic Antigen; D006023:Glycoproteins; D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; C063684:pregnancy-specific beta-1-glycoprotein 7; D004247:DNA