Studies in pig heart tissue on various 60,000 Da phosphoproteins.
Pig heart tissue have been shown to contain 3 different 60,000 Da phosphoproteins. Different purification procedures were used in order to separate them, suggesting that the 3 phosphoproteins differ in their environmental parameters. The 2 major ones appear essentially as peripheral phosphoproteins that are associated with cellular membranes through ionic forces, whereas the third minor phosphoprotein behaves as an integral plasma membrane protein. The three phosphoproteins also differ in their relative amount of phosphorylated serine, threonine and tyrosine residues after in vitro protein kinase assay. Evidence that the 3 phosphoproteins are related arises from the similarity between their respective phosphopeptide maps after partial hydrolysis with proteases, an experiment that also points out relatedness in primary structure between them and the transforming protein of Rous sarcoma virus, pp60v-src. The 3 phosphoproteins, however, do not appear to be immunologically related to pp60v-src since none of them is immunoprecipitated by sera that precipitate pp60v-src. The possibility that the three 60,000 Da phosphoproteins under study represent 3 differentially localized and phosphorylated products of c-src and/or c-src related genes is discussed.
Guesdon
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F
Institut Curie-Biologie, Centre Universitaire, Orsay, France.
David-Pfeuty
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T
D000818:Animals; D002461:Cell Line, Transformed; D008565:Membrane Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology; D008970:Molecular Weight; D009206:Myocardium / Q000032:analysis*; D015688:Oncogene Protein pp60(v-src); D010750:Phosphoproteins / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins / Q000276:immunology; D016392:Proto-Oncogene Proteins pp60(c-src); D012191:Retroviridae Proteins / Q000276:immunology; D012508:Sarcolemma / Q000032:analysis*; D013552:Swine
D008565:Membrane Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D012191:Retroviridae Proteins; D015688:Oncogene Protein pp60(v-src); D016392:Proto-Oncogene Proteins pp60(c-src)