Role of ERK1/ERK2 and p70(S6K) pathway in insulin signalling of protein synthesis

The signalling pathways by which insulin triggers protein synthesis were st udied using an antisense strategy to deplete ERK1/ERK2 and rapamycin to inh ibit the p70(S6K) pathway. The results indicated that ERK1/ERK2 principally regulated the amount of the protein synthesis machinery available in the c ell while the p70(S6K) pathway contributed to modulating its activation in response to insulin, ERK1/ERK2 also mediated in a small proportion of insul in-stimulated protein synthesis which included the induction of c-fos prote in. When c-fos induction was blocked the majority of insulin-stimulated pro tein synthesis still occurred and thus did not require transcriptional regu lation of c-fos or its targets. (C) 1999 Federation of European Biochemical Societies.