Elucidation of mechanisms regulating cell cycle progression is of fundamental importance for cell and cancer biology. Although several genes and signaling pathways are implicated in G1-S regulation, less is known regarding the mechanisms controlling cell cycle progression through G2 and M phases. We report that extracellular signal-regulated kinase 5 (ERK5), a member of the mitogen-activated protein kinases, is activated at G2-M and required for timely mitotic entry. Stimulation of ERK5 activated nuclear factor kappaB (NFkappaB) through ribosomal S6 kinase 2 (RSK2)-mediated phosphorylation and degradation of IkappaB. Furthermore, selective inhibition of NFkappaB at G2-M phases substantially delayed mitotic entry and inhibited transcription of G2-M-specific genes, including cyclin B1, cyclin B2, Plk-1, and cdc25B. Moreover, inhibition of NFkappaB at G2-M diminished mitosis induced by constitutive activation of ERK5, providing a direct link between ERK5, NFkappaB, and regulation of G2-M progression. We conclude that a novel ERK5-NFkappaB signaling pathway plays a key role in regulation of the G2-M progression.
Pubmed ID: 17452529 RIS Download
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Cell line HeLa is a Cancer cell line with a species of origin Homo sapiens
View all literature mentionsCell line HEK293 is a Transformed cell line with a species of origin Homo sapiens (Human)
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