title: Trafficking of MHC molecules to the cell surface creates dynamic protein patches.
abstract: Major histocompatibility complex class I (MHC-I) molecules signal infection or transformation by engaging receptors on T lymphocytes. The spatial organization of MHC-I on the plasma membranes is important for this engagement. We and others have shown that MHC-I molecules, like other membrane proteins, are not uniformly distributed, but occur in patches in the plasma membrane. Here, we describe the temporal details of MHC-I patch formation and combine them with the spatial details, which we have described earlier, to yield a comprehensive quantitative description of patch formation. MHC-I is delivered to the plasma membrane in clathrin-coated vesicles, arriving at a rate of ∼2.5×10(-3) μm(-1) min(-1) (or about two arrivals per minute over the whole cell). The vesicles dock and fuse at non-random, apparently targeted, locations on the membrane and the newly delivered MHC-I molecules form patches that are a few hundred nanometers in diameter. The patches are maintained at steady state by a dynamic equilibrium between the rate of delivery and the rate of hindered diffusion of MHC-I molecules out of the patches (caused by components of the actin cytoskeleton).
authors.affiliation: The Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben Gurion University of the Negev, Beer-Sheva, 8410501 Israel.
authors.forename: Daniel
authors.identifier: 0000-0002-9207-5848
authors.initials: D
authors.lastname: Blumenthal
authors.affiliation: Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Edidin
authors.affiliation: The Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben Gurion University of the Negev, Beer-Sheva, 8410501 Israel glevi@bgu.ac.il.
authors.forename: Levi A
authors.identifier: 0000-0002-7909-100X
authors.initials: LA
authors.lastname: Gheber
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006835:Hydrazones / Q000494:pharmacology; D021621:Imaging, Three-Dimensional; D051379:Mice; D021381:Protein Transport / Q000187:drug effects; D022142:Secretory Vesicles / Q000187:drug effects / Q000378:metabolism
chemical_list: D015395:Histocompatibility Antigens Class I; D006835:Hydrazones; C511794:N'-(3,4-dihydroxybenzylidene)-3-hydroxy-2-naphthahydrazide; D049452:Green Fluorescent Proteins
keywords: FRAP; Fluorescence recovery after photobleaching; MHC-I; Major histocompatibility complex class I; Membrane trafficking; Obstructed diffusion; TIRFM; Total internal reflection fluorescence microscopy