Lab Home | Phone | Search
Center for Nonlinear Studies  Center for Nonlinear Studies
 Home 
 People 
 Current 
 Affiliates 
 Alumni 
 Visitors 
 Students 
 Research 
 ICAM-LANL 
 Quantum 
 Publications 
 Publications 
 2007 
 2006 
 2005 
 2004 
 2003 
 2002 
 2001 
 2000 
 <1999 
 Conferences 
 Workshops 
 Sponsorship 
 Talks 
 Colloquia 
 Colloquia Archive 
 Seminars 
 Postdoc Seminars Archive 
 Quantum Lunch 
 CMS Colloquia 
 Q-Mat Seminars 
 Q-Mat Seminars Archive 
 Archive 
 Kac Lectures 
 Dist. Quant. Lecture 
 Ulam Scholar 
 Colloquia 
 
 Jobs 
 Students 
 Summer Research 
 Student Application 
 Visitors 
 Description 
 Past Visitors 
 Services 
 General 
 PD Travel Request 
 
 History of CNLS 
 
 Maps, Directions 
 CNLS Office 
 T-Division 
 LANL 
 
Thursday, December 16, 2010
2:00 PM - 3:00 PM
CNLS Conference Room (TA-3, Bldg 1690)

Postdoc Seminar

Mechanistic model of lipid raft regulation of IgE receptor signaling

Dipak Barua
Theoretical Biology and Biophysics Group, LANL , CNLS

Lipid rafts are discrete regions in the plasma membrane enriched in cholesterol and spingolipids. They are thought to play an important role in IgE receptor signaling. The rafts preferentially localize the key IgE receptor signaling pro- teins inside the raft regions while exclude the phosphatases into the non-raft region of the membrane. Such raft-localization allegedly protects the proteins from dephosphorylation by phosphatases. This allows the proteins to remain phospohrylated and induce signaling for longer time periods. However, con- tradictory experimental data showing rapid dephosphorylation of raft-localized proteins argues for no raft protection of phosphorylated proteins. Here, we aim to resolve the existing controversies and elucidate the actual mechanism of lipid raft function. Through our model analysis, we show that lipid rafts indeed protect signaling proteins from ephosphorylation. Our results indicate rapid dephosphorylation kinetics for aft-localized proteins even at strong levels of lipid raft protection. In addition, we show how the life-time of lipid rafts compromise their ability to protect protein phosphorylation. At life time less than a second, lipid rafts become incompetent to o er protection to phospho- rylated proteins. On the other hand, at life-times longer than 10 sec, protein dephosphorylation kinetics in the model deviates from experimental data. The model therefore reveals a life-time of 3 􀀀 10 sec for any signal competent lipid raft in the plasma membrane.

Host: Peter Loxley, loxley@lanl.gov