In vitro acetylation of rat pulmonary surfactant-associated glycoprotein(s) A primary translation products.
The primary translation products of pulmonary surfactant-associated glycoprotein(s) A, the major apolipoprotein in mammalian surfactants, exhibit extensive charge heterogeneity. After in vitro translation of poly(A)+ mRNA from rat lung, the primary translation products of glycoprotein(s) A were identified as a charge train of five proteins of 26 kDa (pI 4.6-5.0), the predominant forms being the more acidic members (pI less than 4.8). Inhibition of acetylation during in vitro translation of rat lung poly(A)+ mRNA resulted in a predominance of the more basic isoforms (pI greater than or equal to 4.8). Intracellular forms of glycoprotein(s) A were immunoprecipitated from rat Type II epithelial cells after treatment with tunicamycin or after deglycosylation with endoglycosidase H. Five intracellular precursors consisting primarily of acidic members of the charge train were identified, this being consistent with the intracellular acetylation of the protein. In contrast, canine glycoprotein(s) A translation products consisted of only three proteins of 26 kDa (pI 4.8-5.0), in which most of the radiolabel was concentrated in the more basic components. Acetylation may account for some, but not all, of the charge heterogeneity in the primary translation products and processed forms of surfactant-associated glycoprotein(s) A in the rat.
Weaver
T E
TE
Hull
W M
WM
Ross
G
G
Whitsett
J A
JA
D000107:Acetylation; D000818:Animals; D002478:Cells, Cultured; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D004848:Epithelium / Q000378:metabolism; D007163:Immunosorbent Techniques; D007525:Isoelectric Focusing; D008168:Lung / Q000032:analysis / Q000378:metabolism; D008297:Male; D008970:Molecular Weight; D011061:Poly A / Q000378:metabolism; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D011663:Pulmonary Surfactants / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D011663:Pulmonary Surfactants; D012333:RNA, Messenger; D011061:Poly A