Reduced levels of ADP-ribosylatable elongation factor-2 in aged and SV40-transformed human cell cultures.
The elongation step is involved in the regulation of protein synthesis during the cell cycle, environmental stress, ageing and transformation. Using a diphtheria toxin-mediated assay for measuring the levels of ADP-ribosylatable elongation factor EF-2, we have observed an irreversible decrease of up to 64% in the amount of ADP-ribosylatable EF-2 in normal diploid human fibroblasts MRC-5 undergoing ageing in vitro. However, a similar decrease in low serum-associated G0/G1-arrested cells is reversible both in MRC-5 cells and in their SV40-transformed counterparts. Reduced levels of ADP-ribosylatable EF-2 could account for the slowing-down of protein synthesis during cell cycle arrest and during cellular ageing in culture.
Riis
B
B
Department of Chemistry, Aarhus University, Denmark.
Rattan
S I
SI
Derventzi
A
A
Clark
B F
BF
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D002453:Cell Cycle; D002470:Cell Survival; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D010441:Peptide Chain Elongation, Translational; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000378:metabolism*; D013539:Simian virus 40
D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D000246:Adenosine Diphosphate Ribose