Mutated in Colorectal Cancer (MCC): a centrosomal protein that relocalizes to the ncMTOC during intestinal cell differentiation

Abstract

Mutated in Colorectal Cancer (MCC) encodes a coiled-coil protein implicated, as its name suggests, in the pathogenesis of hereditary human colon cancer. To date, however, the contributions of MCC to intestinal homeostasis remain unclear. Here, we examine the subcellular localization of MCC, both at the mRNA and protein levels, in the adult intestinal epithelium. Our findings reveal that Mcc transcripts are restricted to proliferating crypt cells, including Lgr5+ stem cells, and that Mcc protein is distinctly associated with the centrosome in these cells. Upon intestinal cellular differentiation, Mcc is redeployed to the non-centrosomal microtubule organizing center (ncMTOC) at the apical domain of villus cells. Using intestinal organoids, we show that the shuttling of the Mcc protein depends on phosphorylation by Casein Kinases 1{delta}/{varepsilon}, which are critical modulators of WNT signaling. Together, our findings support a putative role for MCC in establishing and maintaining the cellular architecture of the intestinal epithelium as a component of both the centrosome and ncMTOC.