Naslov
Molecular cloning and expression of a new rat liver cell-CAM 105 isoform

Autori
Čulić, Ognjen ; Huang, Q-H ; Flanagan, D. ; Hixson, D. ; Lin, S-H.

Izvornik
Biochemical journal (London. 1984) (0264-6021) 285 (1992), 1; 47-53

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
cell-CAM 105 ; cell adhesion ; isoform

Sažetak
An hepatocyte cell-adhesion molecule (cell-CAM105) was recently shown to be identical with the liver plasma-membrane ecto-ATPase. This protein has structural features of the immunoglobulin superfamily and is homologous with carcinoembryonic antigen proteins. We have cloned a cDNA encoding a new form of the cell-CAM105 which is a variant of the previously isolated clone. In addition to having a shorter cytoplasmic domain, the new isoform also has substitutions clustered in the first 130 amino acids of the extracellular domain. Both of these isoforms are expressed on the surface of hepatocytes with the shorter variant being the predominant form. The previously isolated cell-CAM105 (long form) has more potential phosphorylation sites than does the new isoform (short form). Both isoforms are found to be phosphorylated after incubation with [32P]phosphate in vitro, with the long form being phosphorylated to a significantly higher extent. This observed differential phosphorylation could be one of the mechanisms for the regulation of isoform functions. Using antipeptide antibodies specific for the long form and antibodies that are reactive with both isoforms, we have shown that both isoforms are localized in the canalicular domain of hepatocytes. The sequence differences between these two isoforms suggest that they are probably derived from different genes rather than from alternative splicing.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

POVEZANOST RADA