Cyclic AMP Blocks Cell Growth through Raf-1-Dependent and Raf-1-Independent Mechanisms
AUTOR(ES)
Dumaz, Nicolas
FONTE
American Society for Microbiology
RESUMO
It is widely accepted that cyclic AMP (cAMP) can block cell growth by phosphorylating Raf-1 on serine 43 and inhibiting signaling to extracellular signal-regulated protein kinase. We show that the suppression of Raf-1 by cAMP is considerably more complex than previously reported. When cellular cAMP is elevated, Raf-1 is phosphorylated on three residues (S43, S233, and S259), which work independently to block Raf-1. Both Ras-dependent and Ras-independent processes are disrupted. However, when cAMP-insensitive versions of Raf-1 are expressed in NIH 3T3 cells, their growth is still strongly suppressed when cAMP is elevated. Thus, although Raf-1 appears to be an important cAMP target, other pathways are also targeted by cAMP, providing alternative mechanisms that lead to suppression of cell growth.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=133826Documentos Relacionados
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