In:
Molecular Biology of the Cell, American Society for Cell Biology (ASCB), Vol. 11, No. 3 ( 2000-03), p. 929-939
Abstract:
Apoptosis causes characteristic morphological changes in cells, including membrane blebbing, cell detachment from the extracellular matrix, and loss of cell–cell contacts. We investigated the changes in focal adhesion proteins during etoposide-induced apoptosis in Rat-1 cells and found that during apoptosis, p130cas (Crk-associated substrate [Cas]) is cleaved by caspase-3. Sequence analysis showed that Cas contains 10 DXXD consensus sites preferred by caspase-3. We identified two of these sites (DVPD 416 G and DSPD 748 G) in vitro, and point mutations substituting the Asp of DVPD 416 G and DSPD 748 G with Glu blocked caspase-3-mediated cleavage. Cleavage at DVPD 416 G generated a 74-kDa fragment, which was in turn cleaved at DSPD 748 G, yielding 47- and 31-kDa fragments. Immunofluorescence microscopy revealed well-developed focal adhesion sites in control cells that dramatically declined in number in etoposide-treated cells. Cas cleavage correlated temporally with the onset of apoptosis and coincided with the loss of p125FAK (focal adhesion kinase [FAK]) from focal adhesion sites and the attenuation of Cas–paxillin interactions. Considering that Cas associates with FAK, paxillin, and other molecules involved in the integrin signaling pathway, these results suggest that caspase-mediated cleavage of Cas contributes to the disassembly of focal adhesion complexes and interrupts survival signals from the extracellular matrix.
Type of Medium:
Online Resource
ISSN:
1059-1524
,
1939-4586
DOI:
10.1091/mbc.11.3.929
Language:
English
Publisher:
American Society for Cell Biology (ASCB)
Publication Date:
2000
detail.hit.zdb_id:
1474922-1
SSG:
12
