Focal adhesion membrane is dotted with protein islands and partitioned for molecular hop diffusion
Year: 2021
Type: preprint
Abstract: Using the ultrafast camera system and new theories for hop diffusion described in the companion paper, we for the first time demonstrated that membrane molecules undergo hop diffusion among the compartments in the bulk basal plasma membrane (PM), with virtually the same compartment sizes (108 nm) as those in the bulk apical PM and the same dwell lifetimes within a compartment (10 and 24 ms for the phospholipid and transferrin receptor, respectively), suggesting that the basic structures and molecular dynamics are very similar in the bulk regions of the apical and basal PMs. Ultrafast PALM and single-molecule imaging revealed that the focal adhesion (FA) is mostly a fluid membrane, partitioned into ∼74-nm compartments where transferrin receptor and β3 integrin undergo hop diffusion, and that the FA membrane is sparsely dotted with 51-nm diameter paxillin islands, where many other FA proteins probably assemble (compartmentalized archipelago model). β3 integrin intermittently associates with the paxillin islands, dynamically linking them to the extracellular matrix. Summary An ultrafast camera with single fluorescent-molecule sensitivities developed by Fujiwara et al. reveals that the focal adhesion membrane is dotted with protein islands and partitioned for molecular hop diffusion, and integrin β3 molecules become temporarily immobilized at the islands.
Language: English
Subfield: Immunology and Allergy
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funders: Northwestern University, Ministry of Education, Culture, Sports, Science and Technology, University of New South Wales, University of British Columbia, University of Tsukuba, Japan Society for the Promotion of Science, Japan Science and Technology Agency, Core Research for Evolutional Science and Technology
Awards: G1607776443, G1816395680, Dynamic focal adhesion molecular islands as revealed by super-spatiotemporal-resolution single fluorescent-molecule localization microscopy, G2521286739, Regulation mechanisms of receptor activity by glycolipids as revealed by high-resolution single-molecule imaging, G3400316188, G4914847639, Development of high-speed super-resolution membrane skeleton elasticity mapping and its application to cell motility analysis, G5650811463, G6718509927, G6959819254, G7139196931, Signal transduction by transient molecular complexes and its regulation by actin membrane skeleton: single-molecule tracking study, Revealing the nano-liquid signaling platform by developing the ultrafast single-molecule super-resolution method, Direct single-molecule observation of the elementary process of molecular complex formation regulated by the compartmentalized plasma membrane, G7874442324, G7879866177, G7994459956, 高精度1分子観察によるエクソソーム膜動態の解明
OpenAlex ID: W3208024485