This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Mednieks, M.I. Articles by Hand, A.R. Search for Related Content PubMed PubMed Citation Articles by Mednieks, M.I. Articles by Hand, A.R. Social Bookmarking                         What's this?

Exocytosis in Rat Parotid Acini After in vitro Treatment with Forskolin is Accompanied by Cellular Redistribution of Regulatory Subunits of Cyclic AMP-dependent Protein Kinase

Laboratory of Oral Biology and Physiology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892

L.F. Cheng

Laboratory of Oral Biology and Physiology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892

A.R. Hand

Laboratory of Oral Biology and Physiology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892

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, R_I and R_II subunits and a 35-to-40-kdal fragment were present in approximately equal amounts throughout the incubation. Azido labeling of R_II appeared either to increase or to remain unchanged, while that of R_I 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.

Journal of Dental Research, Vol. 65, No. 8, 1057-1063 (1986)
DOI: 10.1177/00220345860650080401


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?