Our proposed studies will use the measurement of lateral diffusion of specific membrane proteins to study the lateral organization and dynamics of plasma membrane components. A major objective will be to further characterize the cytoplasmic and extracellular matrix factors which restrict the lateral mobility of components of animal cell membranes. Using various biological and physical means, we will perturb the interactions of membrane proteins with cellular structures and measure any resultant changes in lateral mobility using the fluorescence recovery after photobleaching (FRAP) technique. The results of these studies will allow us to identify those moieties of both the membrane proteins themselves and the structures peripheral to the membrane which are crucial to restraining lateral mobility. Using biophysical analysis, we will attempt to identify the mechanisms by which proteins are restricted in their lateral motions. Using recently developed digitized fluorescence microscopy (DFM) techniques in combination with the photobleaching method, we will ascertain whether the lateral mobility of membrane proteins consists of simple, isotropic dif- fusion or is a more complex process involving membrane flow and/or anisotropic diffusion. The feasibility of using DFM technology to study the kinetics of antigen aggregation reactions (patching) will be explored. It is anticipated that information generated in this project will ultimately lead to a deepened understanding of plasma membrane organization in normal and diseased states.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM041402-01
Application #
3299587
Study Section
Biophysics and Biophysical Chemistry B Study Section (BBCB)
Project Start
1988-12-01
Project End
1993-11-30
Budget Start
1988-12-01
Budget End
1989-11-30
Support Year
1
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Liu, Ping; Ridilla, Marc; Patel, Pratik et al. (2017) Beyond attachment: Roles of DC-SIGN in dengue virus infection. Traffic 18:218-231
Liu, Ping; Weinreb, Violetta; Ridilla, Marc et al. (2017) Rapid, directed transport of DC-SIGN clusters in the plasma membrane. Sci Adv 3:eaao1616
Jacobson, Ken; Liu, Ping (2016) Complexity Revealed: A Hierarchy of Clustered Membrane Proteins. Biophys J 111:1-2
Garcia-Parajo, Maria F; Cambi, Alessandra; Torreno-Pina, Juan A et al. (2014) Nanoclustering as a dominant feature of plasma membrane organization. J Cell Sci 127:4995-5005
Itano, Michelle S; Graus, Matthew S; Pehlke, Carolyn et al. (2014) Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites. Front Phys 2:
Liu, Ping; Wang, Xiang; Itano, Michelle S et al. (2014) Low copy numbers of DC-SIGN in cell membrane microdomains: implications for structure and function. Traffic 15:179-96
Liu, Ping; Wang, Xiang; Itano, Michelle S et al. (2012) The formation and stability of DC-SIGN microdomains require its extracellular moiety. Traffic 13:715-26
Navaratnarajah, Punya; Steele, Bridgett L; Redinbo, Matthew R et al. (2012) Rifampicin-independent interactions between the pregnane X receptor ligand binding domain and peptide fragments of coactivator and corepressor proteins. Biochemistry 51:19-31
Thompson, Nancy L; Navaratnarajah, Punya; Wang, Xiang (2011) Measuring surface binding thermodynamics and kinetics by using total internal reflection with fluorescence correlation spectroscopy: practical considerations. J Phys Chem B 115:120-31
Neumann, Aaron K; Itano, Michelle S; Jacobson, Ken (2010) Understanding lipid rafts and other related membrane domains. F1000 Biol Rep 2:31

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