SUMO-1 Mapping in the Human Genome Andits Implications for Transcription Control

Download or read book SUMO-1 Mapping in the Human Genome Andits Implications for Transcription Control written by Hui-Wen Liu and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: SUMOylation, a post-translational modification with SUMO proteins covalently conjugated to a variety of proteins, regulates a range of cellular processes, including cell proliferation and maintenance of genome stability. In this study, we investigated how SUMO-1 functions as a chromatin mark on the human genome during cell cycle progression by ChIP-seq approach. Surprisingly, despite the known repressive role of SUMOylation on histones, we found that SUMO-1 localizes to the promoters of constitutively active genes involved in protein translation and proliferation during interphase. For example, ribosomal protein genes; and SUMO-1 marks on these promoters were absent during mitosis. In addition, SUMO-1 association on the promoters recruits RNAPII, and depletion of SUMO-1 leads to down regulation of those ribosomal protein genes, suggesting a positive role of SUMO-1 in gene activation. To further elucidate how SUMOylation regulates transcription process related to protein synthesis, we identified that SUMO-1 marks the promoters via the Scaffold Associated Factor B (SAFB) protein. The results showed that SAFB is SUMOylated, and depletion of SAFB caused the decrease of SUMO-1 marks on the promoters of those housekeeping genes transcribed by RNAPII. In addition, depletion of SAFB decreased the splicing of the mRNAs and disrupted the organization of Cajal body, which is important for snRNP and snoRNP biogenesis. All these findings suggested that SUMOylation plays an important role in the regulatory process for transcription initiation and splicing of mRNA of ribosomal protein genes.