Matthew J. Camiolo

1st Year Graduate Student

Department: School of Medicine

Graduate Program: Genetics

Advisor: Lloyd Trotman (rotating)


Abstract (rotation):

Advisor: Dr. Ken-Ichi Takemaru, Department of Pharmacological Sciences, SBU

Title:  7SK RNA IS A RIBOREGULATOR FACILITATING THE DISSOCIATION OF THE pTEF-B COMPLEX FROM TRANSCRIPTION SITES

Matthew Camiolo, Kannanganattu V. Prasanth, Grace Chan, Laurence Denis, Tetsuya Nakamura and David L. Spector

Non-protein coding RNAs (ncRNAs) play important roles in various aspects of gene regulation. As a part of the search for ncRNAs that are retained in various sub-nuclear compartments, we identified 7SK RNA to be localized to nuclear speckles or interchromatin granule clusters (IGCs). 7SK RNA, in association with Hexim 1 and 2, is involved in the inhibition of transcriptional elongation by RNA polymerase II (RNA pol II) (Blencowe BJ, 2002). Inhibition occurs via sequestration of the active pTEF-B kinase complex (CDK 9 and Cyclin-T1) that is involved in phosphorylating the C terminal domain of RNA pol II. Our results show that 7SK RNA transiently associates with a stably integrated reporter gene locus during its transcriptional inactivation and its presence correlates with the displacement of pTEF-B components from the locus. Furthermore, knock-down of 7SK RNA by specific antisense oligonucleotides delays the disassociation of pTEF-B components from the inactivating gene locus. Importantly, knock-down of 7SK RNA resulted in transcriptional up-regulation of this RNA pol II transcribed reporter locus. In addition, 7SK knock-down also resulted in the mislocalization of IGC constituents in a transcription-dependent manner. These results strongly suggest that 7SK RNA negatively regulates RNA pol II transcription by facilitating the disassociation of the pTEF-B complex from the site of transcription during gene inactivation.