Project description:Gene expression programs depend on sequence-specific DNA binding transcription factors, but the mechanisms that control the selective binding of these factors in a chromosomal and genomic context remain enigmatic. Here, we show that two master regulators of B-cell fate, namely EBF1 and RBP-jk, show variable genome-wide chromosome distribution in two related B-lymphocyte lines carrying different forms of Epstein-Barr Virus (EBV) latency. The latency-type specific EBV-encoded EBNA2 colocalized with RBP-jk and EBF1 at induced binding sites. Colocalization of EBF1, RBP-jk, and EBNA2 correlated with transcriptional activation. Conditional expression or repression of EBNA2 lead to a rapid alteration in RBP-jk and EBF1 binding. Biochemical and shRNA depletion studies provide evidence for cooperative assembly at co-occupied sites. These findings reveal that non-DNA binding cofactors can facilitate combinatorial interactions to induce new patterns of transcription factor occupancy and gene programming Examination of EBNA2/EBF1/EBP-jk binding in MutuI and LCL cell lines
Project description:We derived two novel rpESC lines and characterized their microRNA signature by Solexa deep sequencing. By characterizing their microRNA signature, we identified 91 novel microRNAs, except those are also detected in other primate ESCs. Moreover, these two novel rpESCs display a unique microRNA signature, comparing to their biparental counterpart ESCs.