Differential phosphorylation of ribosomal acidic proteins from yeast cell by two endogenous protein kinases: casein kinase-2 and 60S kinase.
The native 80S ribosomes isolated from Saccharomyces cerevisiae (strain W303) cells was phosphorylated by two endogenous protein kinases: multifunctional casein kinase-2 (CK-2) and specific 60S kinase. Three acidic proteins within the 60S ribosomal subunit: YP1 beta, YP1 beta' and YP2 alpha are phosphorylated by both kinases. The other two proteins: YP1 alpha and YP2 beta are predominantly phosphorylated by CK-2 but not by 60S kinase. This was confirmed in the experiment with the recombinant protein, YP2 beta, as a substrate, which is practically not phosphorylated by specific 60S kinase. These results together with the previous data based on the target amino-acid sequences suggest that, in addition to the multifunctional casein kinase-2 and specific 60S kinase, there exist probably other protein kinase(s) which phosphorylate the ribosomal acidic proteins in the cell.
Szyszka
R
R
Department of Molecular Biology, Maria Curie-Skłodowska University, Lublin, Poland.
Boguszewska
A
A
Grankowski
N
N
Ballesta
J P
JP
D047390:Casein Kinase II; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
D005656:Fungal Proteins; D012269:Ribosomal Proteins; C083550:60S ribosomal protein kinase; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases