TY - JOUR
T1 - Archipelago architecture of the focal adhesion
T2 - Membrane molecules freely enter and exit from the focal adhesion zone
AU - Shibata, Akihiro C.E.
AU - Fujiwara, Takahiro K.
AU - Chen, Limin
AU - Suzuki, Kenichi G.N.
AU - Ishikawa, Yoshiro
AU - Nemoto, Yuri L.
AU - Miwa, Yoshihiro
AU - Kalay, Ziya
AU - Chadda, Rahul
AU - Naruse, Keiji
AU - Kusumi, Akihiro
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2012/6
Y1 - 2012/6
N2 - 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.
AB - 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.
KW - GPI-anchored protein
KW - Integrin
KW - Single fluorescent-molecule imaging/tracking
KW - Thy1
KW - Transferrin receptor
KW - Transmembrane protein
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U2 - 10.1002/cm.21032
DO - 10.1002/cm.21032
M3 - Article
C2 - 22488960
AN - SCOPUS:85027928106
VL - 69
SP - 380
EP - 392
JO - Cytoskeleton
JF - Cytoskeleton
SN - 1949-3584
IS - 6
ER -