Cand2 links pathological mTORC1 signaling to adverse cardiac remodeling by regulating Grk5 expression
The mechanistic target of rapamycin (mTOR) is a key regulator of pathological remodeling in the heart by activating ribosomal biogenesis and mRNA translation. Inhibition of mTOR in cardiomyocytes is protective, however, a detailed role of mTOR in translational regulation of specific mRNA networks in the diseased heart is largely unknown. A cardiomyocyte genome-wide sequencing approach was used to define mTOR-dependent post-transcriptional gene expression control at the level of mRNA translation. This approach identified the muscle specific protein Cullin-associated NEDD8-dissociated protein 2 (Cand2) as a translationally upregulated gene dependent on the activity of mTOR. Deletion of Cand2 protects the myocardium against pathological remodeling. Mechanistically, we found that Cand2 links mTOR- signaling to pathological cell growth by increasing Grk5 protein expression. Our data suggest that cell-type specific targeting of mTOR might have therapeutic value for adverse pathological cardiac remodeling. Overall design: Comparision of WT mice vs global Cand2 KO mice