Increase in the amount of elongation factor 2 in rat liver by peroxisome proliferators.
The changes in protein phosphorylation during induction and deinduction of peroxisome proliferation in rat liver by three types of proliferators were studied by in vitro phosphorylation assay. Among the variously phosphorylated proteins, an increase during induction and a decrease during deinduction in phosphorylation of P100, a cytosolic protein having a molecular weight of 100 kDa, was most remarkable. The time course of enhancement of phosphorylation by the administration of the proliferators, however, was not parallel with proliferation of peroxisome but with increase in the liver DNA content. Amino acid sequencing of the protein indicated the identity of its N-terminal 17 amino acid residues with those of elongation factor 2 (EF2). Increase in the amount of EF2 by peroxisome proliferators was confirmed by immunoblotting and this was almost parallel with peroxisome proliferation, suggesting that both increase in the amount of EF2 and some changes in phosphorylation activities account for a large increase in in vitro phosphorylation of EF2 by the administration of peroxisome proliferators.
Motojima
K
K
Department of Biochemistry, School of Pharmaceutical Sciences, Toho University, Chiba.
Ohmori
A
A
Takino
Y
Y
Goto
S
S
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D066246:ErbB Receptors / Q000187:drug effects / Q000378:metabolism; D005260:Female; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008830:Microbodies / Q000187:drug effects / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000096:biosynthesis*; D010750:Phosphoproteins / Q000096:biosynthesis*; D010766:Phosphorylation / Q000187:drug effects; D011506:Proteins / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344
D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D010750:Phosphoproteins; D011506:Proteins; D066246:ErbB Receptors