ERK2 stimulates MYC transcription by anchoring CDK9 to the MYC promoter in a kinase activity–independent manner.

The transcription factor MYC regulates cell proliferation, transformation, and survival in response to growth factor signaling that is mediated in part by the kinase activity of ERK2. Because ERK2 can also bind to DNA to modify gene expression, we investigated whether it more directly regulates MYC transcription. We identified ERK2 binding sites in the MYC promoter and detected ERK2 at the promoter in various serum-stimulated cell types. Expression of nuclear-localized ERK2 constructs in serum-starved cells revealed that ERK2 in the nucleus—regardless of its kinase activity—increased MYC mRNA expression and MYC protein abundance. ERK2 bound to the promoter through its amino-terminal insert domain and to the cyclin-dependent kinase CDK9 (which activates RNA polymerase II) through its carboxyl-terminal conserved docking domain. Both interactions were essential for ERK2-induced MYC expression, and depleting ERK impaired CDK9 occupancy and RNA polymerase II progression at the MYC promoter. Artificially tethering CDK9 to the MYC promoter by fusing it to the ERK2 insert domain was sufficient to stimulate MYC expression in serum-starved cells. Our findings demonstrate a role for ERK2 at the MYC promoter acting as a kinase-independent anchor for the recruitment of CDK9 to promote MYC expression. Editor's summary: The kinase ERK2 stimulates gene expression by activating transcription factors and other proteins. Agudo-Ibáñez et al. found that ERK2 also acted in a more direct and kinase-independent manner to induce the expression of the gene encoding MYC. ERK2 tethered the kinase CDK9 to the MYC promoter, where it stimulated the activity of RNA polymerase. Disrupting these interactions reduced MYC abundance. Given the role of ERK2 and MYC in cancer and other diseases, these findings expand our understanding of the functions of ERK2 and reveal a mechanism that may be relevant to the pathogenesis of various diseases in which ERK2 and MYC are implicated. —Leslie K. Ferrarelli [ABSTRACT FROM AUTHOR]