The biosynthesis and fatty acid acylation of the murine erythrocyte sialoglycoproteins.
The biosynthesis and post-translocational processing of the murine erythrocyte sialoglycoproteins gp2 and gp3 have been studied on splenic erythroblasts obtained from mice rendered anemic by treatment with phenylhydrazine. A putative precursor-product relationship has been established between gp3 and a peptide (gp3pr) of apparent Mr = 22,000. No precursor to gp2 has been found. gp3pr was selectively and efficiently converted to gp3 in pulse-chase experiments after a 45-60-min chase. [3H]Palmitate labeled a series of splenic cell proteins, including gp2, gp3, and gp3pr. Chemical analyses indicated that the fatty acid is covalently linked to protein by an ester bond. Splenic cells incorporated [3H]galactose in both gp2 and gp3 but not in gp3pr. The results indicate that the murine sialoglycoproteins are modified in succession by fatty acid acylation and terminal glycosylation. [3H]Palmitate labeling appears to be an early modification that affects concomitantly gp3pr and gp3, suggesting that fatty acid acylation is a cytosolic event not obligatorily coupled to translocation.
D000215:Acylation; D000740:Anemia / Q000097:blood; D000818:Animals; D004912:Erythrocytes / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D008970:Molecular Weight; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000097:blood*; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000097:blood* / Q000302:isolation & purification; D014316:Tritium
D010169:Palmitic Acids; D012795:Sialoglycoproteins; D014316:Tritium; D019308:Palmitic Acid