Regulation of protein mobility via thermal membrane undulations.
The in-plane diffusivelike motion of membrane bound proteins on the surface of cells is considered. We suggest, on the basis of theoretical arguments and simulation, that thermally excited undulations of the lipid bilayer may serve as a mechanism for proteins to hop between adjacent regions on the cell surface separated by barriers composed of internal cellular structure (e.g., the cytoskeleton). We specifically investigate the mobility of band 3 dimer on the surface of red blood cells where the spectrin cytoskeletal meshwork defines a series of "corrals" on the cell surface known to hinder protein motion. Previous models of this system have postulated that the cytoskeleton must deform to allow passage of membrane bound proteins out of these corral regions and have ignored fluctuations of the bilayer. Our model provides a complementary mechanism and we posit that the mobility of real proteins in real cells is likely the result of several mechanisms acting in parallel.
Brown
Frank L H
FL
Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-9510, USA.
D000465:Algorithms; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry; D001692:Biological Transport; D002462:Cell Membrane / Q000737:chemistry; D003198:Computer Simulation; D003599:Cytoskeleton / Q000737:chemistry; D004058:Diffusion; D019281:Dimerization; D004548:Elasticity; D004910:Erythrocyte Membrane / Q000737:chemistry; D005240:Feasibility Studies; D006706:Homeostasis; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry*; D008954:Models, Biological; D008958:Models, Molecular; D009038:Motion; D011487:Protein Conformation; D013049:Spectrin / Q000737:chemistry; D013696:Temperature
D001457:Anion Exchange Protein 1, Erythrocyte; D008051:Lipid Bilayers; D008565:Membrane Proteins; D013049:Spectrin