Postranslational modification, the adding of chemical moieties to proteins after they are translated from RNA, is a common and complex method of regulating the function and abundance of proteins. Ubiquitination, adding one or many ubiquitin molecules to proteins, helps regulate protein turnover by targeting proteins for degradation. Dr. Iannis Aifantis, Ph.D., and collaborators based at the New York University School of Medicine, now report a role for the Ubiquitin-Proteasome System (UPS) in regulating pluripotency and reprogramming in stem cells. The report, published in Cell Stem Cell, describes a global characterization of the UPS, and shows that several key pluripotency factors, including Nanog and Oct4 are UPS targets. Further analysis showed ubiquitination and deubiquitination of the reprogramming factor and oncogene c-Myc is key for controlling reprogramming to the pluripotent state and differentiation of pluripotent stem cells. Targeting the UPS globally or through specific components has implications for both improved reprogramming and differentiation of stem cells into specific lineages. This work was supported through a NYSTEM Institutional Training award to NYU that supported Alexandros Strikoudis (C026880) and forms the basis for a new NYSTEM research award to Dr. Aifantis.
Buckley SM, Aranda-Orgilles B, Strikoudis A, Apostolou E, Loizou E, Moran-Crusio K, Farnsworth CL, Koller AA, Dasgupta R, Silva JC, Stadtfeld M, Hochedlinger K, Chen EI, Aifantis I. Regulation of Pluripotency and Cellular Reprogramming by the Ubiquitin-Proteasome System. Cell Stem Cell, 2012 Dec 7, 11(6):1-16.