TY - JOUR
T1 - Dynamic change in the distribution of alpha5beta1 integrin on isolated ventral membrane
T2 - Effect of divalent cation species
AU - Hirata, Hiroaki
AU - Ohki, Kazuo
AU - Miyata, Hidetake
PY - 2004/10
Y1 - 2004/10
N2 - We investigated the spatial distribution of α5β 1, integrin in isolated ventral plasma membranes (VPMs) of human foreskin fibroblasts in order to elucidate how the interaction of integrin with cytoskeletal and extracellular matrix proteins might affect the integrin distribution. Cells were exposed to the jet of buffer to remove the apical surface and most of cellular organelles. After this treatment VPMs, which adhered to the glass surface, possessed the cellular structures such as fibronectin (FN) fibrils and actin stress fibers. The isolated VPMs thus prepared were employed without fixation to investigate the change in the integrin distribution. In isolated VPMs, α5β1, integrin, labeled with Cy3-tagged anti-integrin antibody, was found to accumulate not only at the tips of stress fibers but also along FN fibrils extending from there. When divalent cations were removed with EDTA, the accumulated integrin was dispersed, and the original pattern of distribution was recovered upon restoration of divalent cations. Talin, an integrin-actin cytoskeleton linker protein, was found to accumulate only at the tips of stress fibers in isolated VPMs, but α5β1, integrin did not exhibit strong accumulation there, indicating that talin played little role in integrin distribution in isolated VPMs. The amount of α-actinin associated with stress fibers was found to drastically decrease in isolated VPMs, which was presumably related to the failure of localization of integrin at the tips of stress fibers. It was also shown that the association of stress fibers to isolated VPMs seemed to be independent of accumulation of integrin.
AB - We investigated the spatial distribution of α5β 1, integrin in isolated ventral plasma membranes (VPMs) of human foreskin fibroblasts in order to elucidate how the interaction of integrin with cytoskeletal and extracellular matrix proteins might affect the integrin distribution. Cells were exposed to the jet of buffer to remove the apical surface and most of cellular organelles. After this treatment VPMs, which adhered to the glass surface, possessed the cellular structures such as fibronectin (FN) fibrils and actin stress fibers. The isolated VPMs thus prepared were employed without fixation to investigate the change in the integrin distribution. In isolated VPMs, α5β1, integrin, labeled with Cy3-tagged anti-integrin antibody, was found to accumulate not only at the tips of stress fibers but also along FN fibrils extending from there. When divalent cations were removed with EDTA, the accumulated integrin was dispersed, and the original pattern of distribution was recovered upon restoration of divalent cations. Talin, an integrin-actin cytoskeleton linker protein, was found to accumulate only at the tips of stress fibers in isolated VPMs, but α5β1, integrin did not exhibit strong accumulation there, indicating that talin played little role in integrin distribution in isolated VPMs. The amount of α-actinin associated with stress fibers was found to drastically decrease in isolated VPMs, which was presumably related to the failure of localization of integrin at the tips of stress fibers. It was also shown that the association of stress fibers to isolated VPMs seemed to be independent of accumulation of integrin.
KW - Affinity regulation
KW - Talin
KW - Ventral membrane
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U2 - 10.1002/cm.20029
DO - 10.1002/cm.20029
M3 - Article
C2 - 15362117
AN - SCOPUS:4744345012
VL - 59
SP - 131
EP - 140
JO - Cell Motility and the Cytoskeleton
JF - Cell Motility and the Cytoskeleton
SN - 1949-3584
IS - 2
ER -