Disruption of focal adhesions mediates detachment during neuronal apoptosis.
Apoptosis participates in the development of the nervous system and in neurodegeneration. The aim of this study was to investigate the mechanisms of detachment of neuronal cells from the extracellular matrix (ECM) during apoptosis. Detachment of Ntera2 neuronal cells was accompanied by decreased surface expression of the beta1 integrin and redistribution of proteins from focal adhesions (FA). FA proteins were cleaved in a discrete sequence: p130cas, then paxillin, then talin. Caspase inhibition prevented detachment and cleavage of paxillin and p130cas, whilst calpain inhibition blocked talin cleavage. Neuronal cells therefore detach as a result of redistribution and caspase-dependent cleavage of focal adhesion proteins. Cleavage occurs sequentially such that critical ECM-integrin survival signalling cascades are severed before disruption of focal adhesion-cytoskeletal links.
Lesay
A
A
School of Biological Sciences, 1.124 Stopford Building, University of Manchester, Manchester M13 9PT, UK.
Hickman
J A
JA
Gibson
R M
RM
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004151:Dipeptides / Q000494:pharmacology; D005109:Extracellular Matrix / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D022001:Focal Adhesions / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D016608:Talin / Q000378:metabolism
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D003598:Cytoskeletal Proteins; D004151:Dipeptides; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D016608:Talin; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C071482:calpeptin; D002154:Calpain; D020169:Caspases