GIBH scientist found that condensin competes with CTCF in regulation of rRNA gene transcription
CCCTC binding factor (CTCF) is a highly conserved zinc-finger protein implicated in diverse regulatory functions in the genome, including transcription activation/repression, chromatin insulation, imprinting, X chromosome inactivation, and high-order chromatin organization. Previous studies show that CTCF could repress the expression of c-Myc and play an important role in cell growth and proliferation and tumorgenesis.
Recently, Dr. Yao and his group in GIBH cooperated with Dr. Pan at GIBH found that ectopic CTCF could augments pre-rRNA transcription, cell size and cell growth in cervical cancer cells. CTCF positively regulates an RNA polymerase I-dependent manner. Examination of the protein sequence of CTCF revealed a putative conserved RRGR motif located in the C-terminal region of CTCF. Mutation of this motif abolishes the effect of CTCF on rRNA gene transcription. Using MS, Dr. Yao’s group identified SMC2 and SMC4, two subunits of condensin complexes that interact with CTCF. Whereas Condensin negatively regulates CTCF-mediated rRNA gene transcription. The results have been published online in the Journal of biological chemistry (http://www.ncbi.nlm.nih.gov/pubmed/23884423).
The research was supported by the “National Natural Science Foundation of China grants 31271391 and 81201580”, the “Guangdong Science and Technology Planning of Province, China Grant 2011A060901019, the “Chinese Academy of Sciences Grant KSZD-EW-Z-003-1-5” and the “100 Talents Project of the Chinese Academy of Sciences, China”.