Regulation of Mammary Stem Cell Quiescence via Post-Translational Modification of DeltaNp63alpha
Annual summary rept. 15 Nov 2011-14 Nov 2012
DARTMOUTH COLL HANOVER NH
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This document is the Annual Summary Report on the training grant awarded to Andrew DeCastro entitled Regulation of Mammary Stem Cell Quiescence via Post-translational Modification of deltaNP63 . Here, we report our findings of the effects of TGF previously validated as a kinase in our kinome screen mediated phosphorylation of deltaNPdelta3 on stem cell behavior and mitotic activity. Task 1 aims to determine the effects of wild-type, phospho-ablative and phospho-mimetic alleles of deltaNP63delta phosphorylation on stem cell behavior in vitro. Thus far, we demonstrate that stem cell enriched populations, as indicated by ALDH1 activity, contain higher concentrations of deltaNP63 deltaRNA. In addition, we demonstrate that the anti-clonogenic effects of TGF are mediated through phosphorylation of deltaNP63 , whdeltach is rescued via ectopic expression of the phospho-ablative mutant deltaNP63 -AA. Tdeltask 2 aims to identify putative deltaNP63 -kinasesdeltaand determine their role in mitotic activation. Here we further characterize TGF -mediated phosphorylation of deltaNP63 . We demonsdeltarate that TGF phosphorylation of NP63 is a destabildeltazing event, and dependent on the proteasomal degradation pathway. We also report a non-canonical pathway in which ALK5 TGF R1 is cleaved from the membrane and translocates to the nucleus, where it phosphorylates deltaNP63 . Due to our focudelta on Task 1 and 2, we have not yet begun our investigation of Aim 3.
- Medicine and Medical Research