Lab Home | Phone | Search
Center for Nonlinear Studies  Center for Nonlinear Studies
 Colloquia Archive 
 Postdoc Seminars Archive 
 Quantum Lunch 
 Quantum Lunch Archive 
 CMS Colloquia 
 Q-Mat Seminars 
 Q-Mat Seminars Archive 
 P/T Colloquia 
 Kac Lectures 
 Kac Fellows 
 Dist. Quant. Lecture 
 Ulam Scholar 
 CNLS Fellowship Application 
 Student Program 
 Past Visitors 
 History of CNLS 
 Maps, Directions 
 CNLS Office 
Monday, November 08, 2010
11:00 AM - 12:00 PM
CNLS Conference Room (TA-3, Bldg 1690)

Postdoc Seminar

Study of protein-RNA interactions by using fluorescence resonance energy transfer (FRET) and single-molecule FRET (smFRET)

Rajan Lamichhane
Wayne State University

In the cell, two classes of macromolecules, RNA and protein, interact to form ribonucleoprotein complexes (RNPs) that have vital structural, catalytic and regulatory roles. Despite their functional importance, the mechanistic details and dynamics of RNPs are poorly understood. For example, alternative splicing is a highly regulated biological process that plays a crucial role in proteomic diversity in eukaryotes, but lacks a detailed mechanistic framework. Recently, single molecule techniques have been developed to investigate inter- and intramolecular interactions using Fluorescence Resonance Energy Transfer (FRET). Single-molecule FRET (smFRET) can provide information about heterogeneity within a population of molecules and dynamic behavior of single molecules, which cannot be observed directly from ensemble measurement. The goal of my research is to investigate protein-RNA interactions in alternative splicing as well as ribosome assembly, another protein-RNA interaction, by using FRET in combination with smFRET. The data show that Polypyrimidine tract binding protein (PTB) causes RNA looping upon binding, supporting a looping mechanism of exon exclusion. Furthermore, a PTB antagonist, Feminizing locus on X (Fox), competes with PTB to reduce looping and promote exon inclusion. Studies of a central junction in 16S rRNA and the primary binding protein that triggers a conformational change in rRNA, S15, show that mutations that drastically alter the junction dynamics at the S15 binding site affect 30S ribosome assembly.

Host: Brian Munsky (CNLS/CCS3) and Jim Werner (CINT)