The post-translational processing of rat pro-atrial natriuretic factor by primary atrial myocyte cultures.
Primary cultures of neonatal rat atrial myocytes were maintained in two different serum-free media for up to 25 days. Reversed-phase high performance liquid chromatography coupled with atrial natriuretic factor (ANF)-specific radioimmunoassay demonstrated that the cultures maintained in our previously described serum-free medium (Glembotski, C.C., and Gibson, T. R. (1985) Biochem. Biophys. Res. Commun. 132, 1008-1017) secreted primarily ANF-(1-126)-like material, whereas those cultures maintained in a different formulation of medium secreted mostly ANF-(99-126)-like material. Cultures that secreted ANF(99-126)-like material were biosynthetically labeled with [35S]cysteine followed by immunoprecipitation of secreted ANF and analysis by reversed-phase, size exclusion, and ion-exchange high performance liquid chromatography. The labeled ANF-(99-126)-like peptide was shown to be chromatographically indistinguishable from other synthetic peptides related to ANF-(99-126). Labeled ANF purified from extracts of the cultured cells was chromatographically indistinguishable from authentic ANF-(1-126), and could be cleaved specifically by thrombin into labeled ANF-(99-126)-like material. These results indicate that primary atrial myocytes maintained under certain serum-free conditions are capable of secreting ANF-related material that is chromatographically indistinguishable from ANF-(99-126), the known circulating form of the hormone. Additional preliminary studies suggest that the presence of glucocorticoids in the culture medium may confer ANF processing ability on cultured myocytes.
Shields
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PP
Biology Department, San Diego State University, California 92182.
Glembotski
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CC
D000818:Animals; D000911:Antibodies, Monoclonal; D009320:Atrial Natriuretic Factor / Q000096:biosynthesis*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D006325:Heart Atria / Q000166:cytology; D009206:Myocardium / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis*; D011499:Protein Processing, Post-Translational; D011863:Radioimmunoassay; D051381:Rats
D000911:Antibodies, Monoclonal; D011498:Protein Precursors; D009320:Atrial Natriuretic Factor