Glomerular Basement Membrane Proteoglycans Are Derived from a Large Precursor

• Published in: The Journal of cell biology Vol. 106; no. 3; pp. 963 - 970
• Main Authors: Klein, David J., Brown, David M., Oegema, Theodore R., Brenchley, Paul E., Anderson, John C., Mark A. J. Dickinson, Horigan, Elizabeth A., Hassell, John R.
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.03.1988; The Rockefeller University Press
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Antibodies; Basement membrane; Basement Membrane - analysis; Basement Membrane - metabolism; Biological and medical sciences; Chondroitin Sulfate Proteoglycans - analysis; Chondroitin Sulfate Proteoglycans - metabolism; Epithelial cells; Fundamental and applied biological sciences. Psychology; Gels; Glycoproteins; Glycosaminoglycans - analysis; Heparan Sulfate Proteoglycans; Heparitin Sulfate - analysis; Heparitin Sulfate - metabolism; Immunoassay; Kidney Glomerulus - analysis; Kidney Glomerulus - metabolism; Male; Mice; Mice, Inbred C57BL; Protein precursors; Protein Precursors - analysis; Protein Precursors - metabolism; Proteins; Proteoglycans; Proteoglycans - analysis; Rats; Rats, Inbred Strains; Sarcoma, Experimental - analysis; Sarcoma, Experimental - metabolism; Sulfates; Tumors; Proteoglycan; Rat; Gel electrophoresis; Rodentia; Glycoproteins; Kidney; Basement membrane; Immunological method; Vertebrata; Mammalia; Molecular model; Glomerulus; Tumor cell
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.106.3.963

The basement membrane heparan sulfate proteoglycan produced by the Englebreth-Holm-Swarm (EHS) tumor and by glomeruli were compared by immunological methods. Antibodies to the EHS proteoglycan immunoprecipitated a single precursor protein (Mr= 400,000) from [35S] methionine-pulsed glomeruli, the same size produced by EHS cells. These antibodies detected both heparan sulfate proteoglycans and glycoproteins in extracts of unlabeled glomeruli and glomerular basement membrane. The proteoglycans contained core proteins of varying size (Mr= 150,000 to 400,000) with a Mr= 250,000 species being predominant. The glycoproteins are fragments of the core protein which lack heparan sulfate side chains. Antibodies to glomerular basement membrane proteoglycan immunoprecipitated the precursor protein (Mr= 400,000) synthesized by EHS cells and also reacted with most of the proteolytic fragments of the EHS proteoglycan. This antibody did not, however, react with the P44 fragment, a peptide situated at one end of the EHS proteoglycan core protein. These data suggest that the glomerular basement membrane proteoglycan is synthesized from a large precursor protein which undergoes specific proteolytic processing.