| First Author | Puente LG | Year | 2005 |
| Journal | Mol Immunol | Volume | 42 |
| Issue | 10 | Pages | 1177-84 |
| PubMed ID | 15829307 | Mgi Jnum | J:97985 |
| Mgi Id | MGI:3576846 | Doi | 10.1016/j.molimm.2004.11.012 |
| Citation | Puente LG, et al. (2005) Phosphatidylinositol-3-kinase regulates PKCtheta activity in cytotoxic T cells. Mol Immunol 42(10):1177-84 |
| abstractText | Protein kinase C (PKC) theta plays a crucial role in T cell activation. We, therefore, examined the regulation of PKCtheta activity in cytotoxic T lymphocytes (CTL). We demonstrated that PMA did not stimulate PKCtheta activation and phospholipase C inhibition did not block anti-CD3-stimulated PKCtheta activation in a CTL clone. This suggests that diacylglycerol is neither sufficient nor required for PKCtheta activation. Furthermore, PKCtheta was only activated in a CTL clone stimulated with plate-bound anti-CD3 but not soluble anti-CD3. However, PMA or cross-linked anti-CD3 stimulated phosphorylation of PKCtheta as measured by a migratory shift, suggesting that phosphorylation was not sufficient for activity. Phosphatidylinositol 3-kinase activity was required for anti-CD3, but not PMA, stimulated phosphorylation and for immobilized anti-CD3-triggered PKCtheta activity. A substantial fraction of PKCtheta was constitutively membrane associated and PMA or CD3 stimulation did not significantly increase membrane association. Our data indicate that phosphorylation of PKCtheta is not a suitable surrogate measurement for PKCtheta activity and that additional, yet to be defined steps, are required for the regulation of PKCtheta enzymatic activity in CTL. |
