RRM
2011 Rustbelt RNA Meeting
RRM
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Poster abstracts
Abstract:
The HIV genome is synthesized as a 9kb polycistronic transcript that undergoes alternative splicing to produce the complete viral protein compliment. Within the HIV genome both donor and acceptor sites are coupled together to determine which of the over 40 transcripts are made and thus which viral proteins are produced. Host proteins are responsible for both the up regulation and down regulation of these sites and play a key role in the viral protein production. ASF (Alternative Splicing Factor) is one such protein that upregulates splicing in the HIV genome. ASF is a serine-arginine rich protein that upregulates splicing by recruiting U1 and U2 snRNP. The protein is roughly 33 kDa in its entirety and consists of three domains, a serine-arginine rich domain and two RNA recognition motifs (RRMs). The two RRM domains (RRM-1 and RRM-2) are responsible for recognition of the RNA and have been shown to bind exonic splicing enhancer (ESE) sequences ESE2 and ESE3 at splice site A7. The mechanism of interaction between ASF and splice site A7 is poorly understood, thus precludes a detailed understanding of how HIV regulates splicing activity at splice site A7. As a step towards gaining more insight, we conducted an isothermal titration calorimetry (ITC) study to understand how much each RRM domain contributes to binding. Also, electron paramagnetic resonance (EPR) studies allow us to probe us the dynamic and structural interactions between ASF and the RNA. Taken together, this work will advance our understanding of the HIV splicing mechanism and may pave the way to novel HIV therapeutics.
Keywords: HIV, alternative splicing
