Chaperone-like activity of mammalian elongation factor eEF1A: renaturation of aminoacyl-tRNA synthetases.
Eukaryotic translational elongation factor eEF1A is known to be responsible for the binding of codon-specific aminoacyl-tRNAs to the ribosome. In this study, we report that in addition to this canonical function, eEF1A is able to promote the renaturation of aminoacyl-tRNA synthetases (ARS) and protect them against denaturation by dilution. The full recovery of the phenylalanyl- (PheRS) and seryl-tRNA synthetase (SerRS) activities was achieved in the presence of 4 microM eEF1A, while bovine serum albumin at similar concentration had no renaturation effect. Remarkably, in vitro renaturation occurs at the molar ratio of eEF1A to ARS equivalent to that found in the cytoplasm of higher eukaryotic cells. The eEF1A.GDP and eEF1A.GTP complexes were shown to be similar in their effect on the phenylalanyl-tRNA synthetase renaturation. Thus, we conclude that the chaperone-like activity of eEF1A might be important for maintaining the enzymes activity in the protein synthesis compartments of mammalian cells.
Lukash
T O
TO
Department of Translation Mechanisms, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnogo Str., Kiev 03143, Ukraine.
Turkivska
H V
HV
Negrutskii
B S
BS
El'skaya
A V
AV
D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002845:Chromatography; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D020648:Peptide Elongation Factor 1 / Q000737:chemistry / Q000378:metabolism*; D010652:Phenylalanine-tRNA Ligase / Q000737:chemistry / Q000378:metabolism; D020673:Protein Renaturation; D011817:Rabbits; D012714:Serine-tRNA Ligase / Q000737:chemistry / Q000378:metabolism
D018832:Molecular Chaperones; D020648:Peptide Elongation Factor 1; D000604:Amino Acyl-tRNA Synthetases; D012714:Serine-tRNA Ligase; D010652:Phenylalanine-tRNA Ligase