Authors:
Dung-Fang Lee, Jie Su, Yen-Sin Ang, Xonia Carvajal-Vergara, Sonia Mulero-Navarro, Carlos F. Pereira, Julian Gingold, Hung-Liang Wang, Ruiying Zhao, Ana Sevilla, Henia Darr, Andrew J.K. Williamson, Betty Chang, Xiaohong Niu, Francesca Aguilo, Elsa R. Flores, Yuh-Pyng Sher, Mien-Chie Hung, Anthony D. Whetton, Bruce D. Gelb, Kateri A. Moore, Hans-Willem Snoeck, Avi Maayan, Christoph Schaniel, & Ihor R. Lemischka
Summary:
Many signals must be integrated to maintain self-renewal and pluripotency in embryonic stem cells (ESCs) and to enable induced pluripotent stem cell (iPSC) reprogramming. However, the exact molecular regulatory mechanisms remain elusive. To unravel the essential internal and external signals required for sustaining the ESC state, we conducted a short hairpin (sh) RNA screen of 104 ESC-associated phosphoregulators. Depletion of one such molecule, aurora kinase A (Aurka), resulted in compromised self-renewal and consequent differentiation. By integrating global gene expression and computational analyses, we discovered that loss of Aurka leads to upregulated p53 activity that triggers ESC differentiation. Specifically, Aurka regulates pluripotency through phosphorylation-mediated inhibition of p53-directed ectodermal and mesodermal gene expression. Phosphorylation of p53 not only impairs p53-induced ESC differentiation but also p53-mediated suppression of iPSC reprogramming. Our studies demonstrate an essential role for Aurka-p53 signaling in the regulation of self-renewal, differentiation, and somatic cell reprogramming.
Source:
Cell Stem Cell; Vol. 11, Issue 2, 179-194 (08/03/12)