Poster abstracts

Poster number 8 submitted by Saba Barezi

Biophysical studies of QRRM1 of hnRNP H1

Saba Barezi (Department of Chemistry, Case Western Reserve University, Cleveland), Dr. Theresa Ramelot (Department of Chemistry and Biochemistry Miami University, Oxford Ohio), Dr. Blanton Tolbert (Department of Chemistry, Case Western Reserve University, Cleveland)

Abstract:
The hnRNP H1 protein is a member of the ubiquitously expressed heterogeneous nuclear ribunucleoproteins (hnRNPs) subfamily. hnRNP H1 has three Quasi-RRM domains and Glycine rich repeats. Studies have shown that hnRNP H1 binds poly G segments with high affinity; however, the binding preferences of each sub Q-RRM are unknown¹. hnRNP H1, like other members of the hnRNP family functions as a trans regulator of alternative splicing. The mechanism of how hnRNP H1 regulates alternative splicing is poorly understood, however as a step toward gaining a better understanding of hnRNP H1 nucleic acid interactions, the solution structure of the Q-RRM1 domain was determined. The solution structure shows Q-RRM1 consists of four anti parallel beta-strands and three alpha-helices in βαββαβα arrangement. Furthermore we used NMR for determining the amino acid residues interacting with nucleic acid to determine the site of interaction on the Q-RMM1. Additionally isothermal titration calorimetry was utilized for studying biophysical properties of the Q-RRM1 interaction with poly G oligos.

References:
1. Jablonski JA, Caputi M (2009) Role of cellular RNA processing factors in human immunodeficiency virus type 1 mRNA metabolism, replication, and infectivity. J Virol 83: 981–992.

Keywords: hnRNP H, Q-RRM