Regulation of polypeptide-chain initiation in rat skeletal muscle. Starvation does not alter the activity or phosphorylation state of initiation factor eIF-2.
In rats, 48-h starvation causes a decrease in the rate of protein synthesis in skeletal (e.g. gastrocnemius) muscle, due largely to impairment of peptide-chain initiation. In other cell types inhibition of initiation is associated with decreased activity and recycling of initiation factor eIF-2, and increased phosphorylation of its alpha-subunit. However, 48-h starvation has no effect on the activity or recycling of eIF-2 measured in extracts of gastrocnemius muscle, or on the level of alpha-subunit phosphorylation. The effects of starvation on peptide-chain initiation in skeletal muscle must therefore involve alterations in other components of the translational machinery.
Cox
S
S
Biological Laboratory, University, Canterbury, England.
Redpath
N T
NT
Proud
C G
CG
D000818:Animals; D015852:Eukaryotic Initiation Factor-2; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D008297:Male; D009132:Muscles / Q000378:metabolism*; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010766:Phosphorylation; D011132:Polyribosomes / Q000378:metabolism / Q000648:ultrastructure; D011506:Proteins / Q000378:metabolism*; D012358:RNA, Transfer, Met / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012270:Ribosomes / Q000378:metabolism; D013217:Starvation
D015852:Eukaryotic Initiation Factor-2; D010448:Peptide Initiation Factors; D011506:Proteins; D012358:RNA, Transfer, Met; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate