The effect of serum deprivation on the initiation of protein synthesis in mouse neuroblastoma cells.
Growth of mouse neuroblastoma cells becomes stationary when cultured in serum-free medium. Within 60 h, the protein-synthesizing capacity of the cells declines to 25% as compared to that of exponentially growing cells. The transitional activity of the crude ribosomal salt washes from serum-deprived and control cells was compared in in vitro protein-synthesizing pH 5 systems. It appears that the ribosomal salt wash from serum-deprived cells has significantly (70%) lost its ability to support the translation of neuroblastoma poly(A)+ RNA. This activity of the ribosomal wash from serum-deprived cells can be restored to control level with rabbit reticulocyte initiation factor eIF-4B only. The ability of the ribosomal wash from serum-deprived cells to support the translation of encephalomyocarditis virus (EMC) and Semliki Forest virus (SFV) 42 S mRNA was tested. We found that EMC-mRNA is efficiently translated with the ribosomal salt wash from serum-deprived cells, whereas on the other hand the translation of SFV 42 S mRNA is severely impaired. Therefore, we conclude that in serum-deprived neuroblastoma cells protein synthesis is regulated in both a quantitative and a qualitative way. Modulation of the activity of initiation factor of protein synthesis eIF-4B is at least partly responsible for the observed (selective) blockade of protein synthesis in serum-deprived cells.
Salimans
M M
MM
van Heugten
H A
HA
van Steeg
H
H
Voorma
H O
HO
D000818:Animals; D001790:Blood Physiological Phenomena; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D004686:Encephalomyocarditis virus / Q000235:genetics; D039642:Eukaryotic Initiation Factors; D005786:Gene Expression Regulation / Q000187:drug effects; D051379:Mice; D009447:Neuroblastoma; D010448:Peptide Initiation Factors / Q000502:physiology; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D012672:Semliki forest virus / Q000235:genetics
D003470:Culture Media; D039642:Eukaryotic Initiation Factors; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012367:RNA, Viral; C031799:eIF-4B