Protein kinases and their protein substrates in free messenger ribonucleoprotein particles and polysomes from mouse plasmacytoma cells.
Eur J Biochem
; 118(2): 379-87, 1981 Aug.
Article
en En
| MEDLINE
| ID: mdl-7285931
ABSTRACT
In free messenger ribonucleoprotein particles (mRNP) and polysomes from plasmacytoma cells, a phosphorylated protein/protein kinase system has been characterized by a combination of oligo(dT)-cellulose chromatography and CsCl isopycnic gradient centrifugation. The presence phosphorylated in vivo has been detected in both types of particles. Endogenous protein phosphorylation occurs in vitro by particle-associated cAMP-independent protein kinase(s) using [gamma-32P]ATP and [gamma-32P]GTP. These kinases are sensitive to hemin action. Analysis of mRNP proteins by gel electrophoresis and autoradiography showed strong analogies between the phosphorylation patterns obtained in vivo and in vitro, suggesting a substrate specificity for the associated enzymes. The phosphorylated proteins have been compared to initiation factors and ribosomal proteins. We have partially purified the cAMP-independent protein kinase activities responsible for the endogenous phosphorylation in free mRNP and polysomes; two activities were identified in free mRNP whereas three activities were found to be associated with polysomes.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasmacitoma
/
Polirribosomas
/
Proteínas Quinasas
/
Ribonucleoproteínas
/
Nucleoproteínas
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Eur J Biochem
Año:
1981
Tipo del documento:
Article