| Autor: |
MEDNIEKS, M. I., CHENG, L. F., HAND, A. R. |
| Předmět: |
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| Zdroj: |
Journal of Dental Research; Aug1986, Vol. 65 Issue 8, p1057-1063, 7p, 3 Black and White Photographs, 3 Charts, 1 Graph |
| Abstrakt: |
Incubation of rat parotid acinar tissue with 1 µmol/L forskolin resulted in progressive exocytosis which was virtually complete after a 30-minute incubation period. Cyclic AMP binding to protein kinase (cA-PK) regulatory (R) subunits, determined by photo-affinity labeling with [32P]-8-azido cyclic AMP, was found to increase in a time-dependent manner in the 10,000-g supernatant fraction of a broken cell preparation. An apparent redistribution of protein kinase R subunits took place in the 600-g supernatant after in vitro treatment of cells with forskolin. In control cells, RI and RII, subunits and a 35-to40-kdal fragment were present in approximately equal amounts throughout the incubation. Azido labeling of RII, appeared either to increase or to remain unchanged, while that of RI decreased in the 600-g pellet. Only type I isozyme R subunits were found in the 600-g pellet in either the absence or presence of forskolin. These findings indicate that a temporal relationship exists between stimulated protein exocytosis and cyclic AMP-dependent protein kinase activation. Forskolin stimulation of adenylate cyclase in salivary gland cells therefore provides a defined system for the study of cyclic AMP-mediated protein secretion. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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