Degradation of fodrin by m-calpain in fibroblasts adhering to fibrillar collagen I gel.
When skin fibroblasts were cultured on fibrillar collagen I gel, we observed rapid degradation of talin, fodrin and ezrin, which are well-known calpain substrates. The protease m-calpain was activated only in cells adhering to fibrillar collagen, whereas micro-calpain was activated in cells adhering to monomeric or fibrillar collagen at the same level. The calpain inhibitor Z-Leu-Leu-aldehyde inhibited degradation of fodrin, but not talin. Degradation of fodrin, alpha-actinin and ezrin was prevented by over-expression of dominant negative m-calpain. However, over-expression of calpastatin, an endogenous calpain inhibitor, had no effect the degradation of these three proteins. These results suggest that m-calpain is responsible for degradation of their membrane proteins via adhesion to fibrillar collagen I gel.
Sato
Kaori
K
Department of Molecular Biology, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan. ksq@mac.com
Hattori
Shunji
S
Irie
Shinkichi
S
Sorimachi
Hiroyuki
H
Inomata
Mitsushi
M
Kawashima
Seiichi
S
D000185:Actinin / Q000378:metabolism; D002154:Calpain / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors / Q000494:pharmacology; D024022:Fibrillar Collagens / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D005782:Gels; D005799:Genes, Dominant; D006801:Humans; D007231:Infant, Newborn; D008840:Microfilament Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D013049:Spectrin; D000099149:Ezrin
D000185:Actinin; D002154:Calpain; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D024022:Fibrillar Collagens; D005782:Gels; D008840:Microfilament Proteins; D010750:Phosphoproteins; D013049:Spectrin; D000099149:Ezrin; C449000:m-calpain