Yu Lu1,2,§, Yuin-Han Loh2,3,4,5,§, Hu Li6,7,8,§, Marcella Cesana2,3, Scott B. Ficarro1,2,9, Jignesh Parikh1,9,10, Nathan Salomonis11, Cheng-Xu Delon Toh4, Stelios T. Andreadis12, C. John Luckey13, James J. Collins6,7,14,*, George Q. Daley2,3,14,15,*, Jarrod A. Marto1,2,9,*.
1 Cancer Biology Department, Dana-Farber Cancer Institute, Boston, MA 02115 USA
2 Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 USA
3 Department of Medicine, Division of Pediatric Hematology Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115 USA
4 A*STAR Institute of Molecular and Cell Biology, Singapore 138673, Singapore
5 Department of Biological Sciences, National University of Singapore, Singapore
6 Department of Biomedical Engineering and Center for BioDynamics, Boston University, Boston, MA 02215 USA
7 Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02118, USA
8 Center for Individualized Medicine, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905 USA
9 Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115 USA
10 Bioinformatics Program, Boston University, Boston, MA 02115 USA
11 Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158 USA
12 Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260 USA
13 Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115 USA
14 Howard Hughes Medical Institute
15 Harvard Stem Cell Institute, Cambridge, MA 02138 USA
§ These authors contributed equally to this work.
* To whom correspondence should be addressed.
Published online in Cell Stem Cell on 8 May 2014.
Using global gene expression and proteomic analyses, we identified a molecular signature in human embryonic and induced pluripotent stem cells that suggested a central regulatory role for RNA splicing in self-renewal. Through genetic and biochemical approaches, we established reciprocal functional links between the master regulatory factor OCT4 and SFRS2, a member of the serine/arginine-rich family of splicing factors. SFRS2 regulates expression of two isoforms of the methyl-DNA binding protein MBD2 that play opposing roles in human ESC and during the reprogramming of fibroblasts. Both the MBD2a isoform expressed in fibroblasts and the MBD2c isoform found in pluripotent cells bind OCT4 and NANOG promoters in human ESC, but only MBD2a interacts with NuRD chromatin remodeling factors. Members of the miR-301 and miR-302 families provide additional regulation by targeting SFRS2 and the somatic specific MBD2a isoform. These data are consistent with a model in which OCT4, SFRS2, and MBD2 participate in a positive feedback loop to regulate proteome diversity in support of self-renewal in pluripotent cells.
Proposed model illustrating a putative positive feedback loop, in which the splicing factor SFRS2 along with microRNAs, tightly controlled by the core pluripotency genes, regulate the expression of MBD2 isoforms that either support (MBD2c) or oppose (MBD2a) expression of OCT4, NANOG, and SOX2 through recruitment of the NuRD complex.
For more information on Jonathan Yuin-Han LOH’s laboratory, please click here.