Nuclear proteome analysis of monkey embryonic stem cells during differentiation.

The nuclear proteome enables, manages, and regulates the genome by the collective actions and interactions of proteins found in the nucleus. We applied a proteomic approach to analyze a nuclear proteome during embryonic stem cell (ESC) proliferation, and 3 and 9 days after initiation of differentiation. The nuclei were isolated from cells and their proteins were separated using 2-DE. Out of about 560 protein spots reproducible detected on any give gel, 49 differentially expressed proteins were identified by Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI TOF/TOF) mass spectrometry. Of them, several nuclear located proteins involved in chromatin remodeling, transcription regulation, apoptosis, cell proliferation, and differentiation were identified including CTBP1, MM-1, RUVBL1, HCC-1, SGTA, SUMO2, and Galectin-1. Functional interaction analysis of differentially expressed proteins revealed that most of nuclear proteins had a direct interaction with c-Myc and p53.