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Archipelago architecture of the focal adhesion: Membrane molecules freely enter and exit from the focal adhesion zone
Author(s) -
Shibata Akihiro C. E.,
Fujiwara Takahiro K.,
Chen Limin,
Suzuki Kenichi G. N.,
Ishikawa Yoshiro,
Nemoto Yuri L.,
Miwa Yoshihiro,
Kalay Ziya,
Chadda Rahul,
Naruse Keiji,
Kusumi Akihiro
Publication year - 2012
Publication title -
cytoskeleton
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 86
eISSN - 1949-3592
pISSN - 1949-3584
DOI - 10.1002/cm.21032
Subject(s) - integrin , extracellular matrix , membrane , focal adhesion , biology , adhesion , microbiology and biotechnology , cell adhesion molecule , cell adhesion , biophysics , cell , biochemistry , materials science , signal transduction , composite material
Abstract The focal adhesion (FA) is an integrin‐based structure built in/on the plasma membrane, mechanically linking the extracellular matrix with the termini of actin stress fibers, providing key scaffolds for the cells to migrate in tissues. The FA was considered as a micron‐scale, massive assembly of various proteins, although its formation and decomposition occur quickly in several to several 10 s of minutes. The mechanism of rapid FA regulation has been a major mystery in cell biology. Here, using fast single fluorescent‐molecule imaging, we found that transferrin receptor and Thy1, non‐FA membrane proteins, readily enter the FA zone, diffuse rapidly there, and exit into the bulk plasma membrane. Integrin β3 also readily enters the FA zone, and repeatedly undergoes temporary immobilization and diffusion in the FA zone, whereas approximately one‐third of integrin β3 is immobilized there. These results are consistent with the archipelago architecture of the FA, which consists of many integrin islands: the membrane molecules enter the inter‐island channels rather freely, and the integrins in the integrin islands can be rapidly exchanged with those in the bulk membrane. Such an archipelago architecture would allow rapid FA formation and disintegration, and might be applicable to other large protein domains in the plasma membrane. © 2012 Wiley Periodicals, Inc