Dynamics and segregation of cell-matrix adhesions in cultured fibroblasts.
Here we use time-lapse microscopy to analyse cell-matrix adhesions in cells expressing one of two different cytoskeletal proteins, paxillin or tensin, tagged with green fluorescent protein (GFP). Use of GFP-paxillin to analyse focal contacts and GFP-tensin to study fibrillar adhesions reveals that both types of major adhesion are highly dynamic. Small focal contacts often translocate, by extending centripetally and contracting peripherally, at a mean rate of 19 micrometers per hour. Fibrillar adhesions arise from the medial ends of stationary focal contacts, contain alpha5beta1 integrin and tensin but not other focal-contact components, and associate with fibronectin fibrils. Fibrillar adhesions translocate centripetally at a mean rate of 18 micrometers per hour in an actomyosin-dependent manner. We propose a dynamic model for the regulation of cell-matrix adhesions and for transitions between focal contacts and fibrillar adhesions, with the ability of the matrix to deform functioning as a mechanical switch.
Zamir
E
E
Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel.
Katz
M
M
Posen
Y
Y
Erez
N
N
Yamada
K M
KM
Katz
B Z
BZ
Lin
S
S
Lin
D C
DC
Bershadsky
A
A
Kam
Z
Z
Geiger
B
B
D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D051419:Paxillin; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D000070876:Tensins; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D014162:Transfection
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003598:Cytoskeletal Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D008840:Microfilament Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011994:Recombinant Proteins; D000070876:Tensins; D013844:Thiazoles; D053778:Thiazolidines; D049452:Green Fluorescent Proteins; D000205:Actomyosin; C037067:latrunculin A