Poster abstracts

Poster number 16 submitted by Yanyan Zhang

Identification of X chromosome inactivation specific transcript (Xist) interacting proteins in vivo

Yanyan Zhang (Chemistry Department, University of Akron), Thomas Leeper (Chemistry Department, University of Akron)

Abstract:
X chromosome inactivation is a dosage compensation strategy that mammals use to balance the protein levels expressed from X chromosome-linked genes between females (XX) and males (XY). This process strategically inactivates one of the X chromosomes in female mammals. Most genes from this inactivated chromosome are silenced except X inactivation specific transcript (Xist) gene. At the onset of X inactivation, Xist gene is transcribed into a large non-coding RNA, which wraps the X-chromosome that is going to be inactivated in cis and recruits certain protein complexes to assist in the inactivation event. The identities of these interacting proteins have not been well defined mainly because of the difficulty to isolate an ¡°active¡± Xist-RNP particle. In order to identify these RNA interacting proteins in vivo, a 14-mer peptide nucleic acid (PNA) complementary to a unique sequence located in the conserved region of Xist RNA is synthesized and covalently linked to a nuclear localization signal (NLS) peptide. The PNA-NLS is incubated with a female human breast cancer cell line and a PNA-assisted identification of RNA binding proteins (PAIR) technique is used to search for X inactivation related proteins. Identification of Xist RNA binding proteins will be used to elucidate the mechanism of X-inactivation.

References:
Current Opinion in Genetics & Development, 2009, 19:122¨C126

Nature protocols, 2006, 1(2), 920-927

Keywords: Xist, PNA, PAIR