| First Author | Dreolini L | Year | 2007 |
| Journal | Biochem Biophys Res Commun | Volume | 356 |
| Issue | 1 | Pages | 207-12 |
| PubMed ID | 17336925 | Mgi Jnum | J:121461 |
| Mgi Id | MGI:3710067 | Doi | 10.1016/j.bbrc.2007.02.100 |
| Citation | Dreolini L, et al. (2007) Activation of LFA-1 by ionomycin is independent of calpain-mediated talin cleavage. Biochem Biophys Res Commun 356(1):207-12 |
| abstractText | Activation of calpains by calcium flux leading to talin cleavage is thought to be an important process of LFA-1 activation by inside-out signalling. Here, we tested the effects of the calcium ionophore ionomycin and calpain inhibitor calpeptin on LFA-1-mediated adhesion of a T cell hybridoma line, cytotoxic T cells and primary resting T cells. Ionomycin activated LFA-1-mediated adhesion of all three types of T cells, and calpeptin inhibited the effects of ionomycin. However, calpeptin also inhibited activation of LFA-1 by PMA, which did not induce calcium flux. Cleavage of talin was undetectable in ionomycin-treated T cells. Furthermore, treatment with ionomycin and calpeptin induced apoptosis of T cells. Inhibitors of phosphatidyl Inositol-3 kinase inhibited activation of LFA-1 by ionomycin, but not by PMA, whereas the protein kinase C inhibitor inhibited the effects of PMA, but not ionomycin. Thus, activation of LFA-1 by ionomycin is independent of calpain-mediated talin cleavage. |
