Synthesis and secretion of alpha 2-macroglobulin by human lung fibroblasts.
Synthesis and secretion of alpha 2-macroglobulin were studied with the human lung fibroblast cell line GM 1379. After incubation with [3H]leucine the cells secreted radioactively labeled alpha 2-macroglobulin consisting of subunits with a molecular weight of 180,000. When the cells were treated with tunicamycin the unglycosylated alpha 2-macroglobulin subunit exhibited a molecular weight of 160,000. Poly(A) +RNA was isolated from the cultured cells and translated in a rabbit reticulocyte lysate. From the translation products an alpha 2-macroglobulin species with a molecular weight of 160,000 was immunoprecipitated. The addition of pancreatic microsoms to the translation mixture resulted in the synthesis of an alpha 2-macroglobulin subunit which had molecular weights of 180,000. Thus, a size of approximately 160,000 for the protein moiety and 20,000 for the carbohydrate portion can be estimated for a subunit of alpha 2-macroglobulin from human lung fibroblasts.
W
W
Budek
M L
ML
Danailov
P
P
Bünning
E G
EG
Afting
D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007930:Leucine / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008970:Molecular Weight; D011061:Poly A / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger; D014415:Tunicamycin / Q000494:pharmacology; D000511:alpha-Macroglobulins / Q000096:biosynthesis*
D012333:RNA, Messenger; D000511:alpha-Macroglobulins; D014415:Tunicamycin; D011061:Poly A; D012313:RNA; D007930:Leucine