Rat liver pp49, a protein that forms complexes with protein kinase CK2, is composed of the beta and the gamma subunits of translation initiation factor eIF-2.
Comparison of the amino acid sequences of two peptides derived from proteolysis of rat liver pp49 identified it as composed of the beta-subunit and the gamma-subunit of eukaryotic initiation factor-2 (eIF-2). Partial purification of rat liver eIF-2 showed that its trimeric form (alpha beta gamma) co-eluted with protein kinase CK2. Heat-inactivated preparations of the trimeric form of eIF-2 inhibited CK2, increasing its Km for beta-casein, as observed with pp49. The form of eIF-2 that lacks the beta-subunit had no effect on CK2. These data indicate that the beta gamma subunits of eIF-2 may complex with CK2 and modulate its activity.
Gil
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Departament de Bioquímica i de Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Plana
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Riera
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Itarte
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D000595:Amino Acid Sequence; D000818:Animals; D047390:Casein Kinase II; D002364:Caseins / Q000378:metabolism; D015852:Eukaryotic Initiation Factor-2 / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D010766:Phosphorylation; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid
D002364:Caseins; D015852:Eukaryotic Initiation Factor-2; D046911:Macromolecular Substances; D010446:Peptide Fragments; D011506:Proteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases