Research ArticlePhysiology

MNK2 Inhibits eIF4G Activation Through a Pathway Involving Serine-Arginine–Rich Protein Kinase in Skeletal Muscle

See allHide authors and affiliations

Science Signaling  14 Feb 2012:
Vol. 5, Issue 211, pp. ra14
DOI: 10.1126/scisignal.2002466

You are currently viewing the editor's summary.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Limiting Muscle Mass

Skeletal muscle mass changes in response to activity, the availability of nutrients, and pathologic loss of muscle mass are associated with long-term bed rest, cachexia-inducing diseases, and starvation. Hu et al. used overexpression, knockout, and knockdown studies to show that the kinase MNK2 had a negative regulatory role on proteins involved in protein synthesis under atrophy-promoting conditions. This was unexpected because MNK2 is also part of a eukaryotic translation initiation complex and is one of the two isoforms capable of phosphorylating a component of that complex on a site associated with promotion of protein synthesis. The negative regulatory effects on protein synthesis machinery appeared to involve a kinase-independent interaction with mTOR, a master regulator of protein synthesis, and a kinase-dependent regulation of another kinase, SRPK, which had not been previously implicated in regulation of protein synthesis.