Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
1992-8-14
pubmed:abstractText
The purpose of this study was to determine how RI alpha, the R subunit of the type I cAMP-dependent protein kinase, is regulated in rabbit ovarian follicles in response to the preovulatory luteinizing hormone surge. When soluble extracts from rabbit preovulatory follicles and 7-day-old corpora lutea were photoaffinity-labeled with 8-N3-[32P]cAMP, 3-fold more RI alpha was detected in corpora lutea than in follicles. Based on DEAE-cellulose chromatography, both type I holoenzyme and free RI alpha increased during luteinization. Western blot analysis of soluble extracts obtained from follicles and corpora lutea at various time points after human chorionic gonadotropin (hCG) injection revealed a 6-10-fold increase in RI alpha protein by 5 h after hCG injection. However, based on Northern blot analysis and solution hybridization/RNase protection assays, this increase in RI alpha protein was not due to an increase in RI alpha mRNA. These results suggested that RI alpha subunit levels were post-transcriptionally regulated. Half-life determinations indicated a 2.1-fold increase in the stability of RI alpha when follicles were incubated in the presence of hCG. The effect of hCG on the stability of RI alpha could also be mimicked by forskolin, thus suggesting that a rise in cAMP levels in follicles during the luteinizing hormone surge plays a role in RI alpha subunit stability. We conclude that RI alpha protein is stabilized in follicles by hCG treatment and the consequent rise in follicular cAMP levels.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14335-44
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:1321143-Affinity Labels, pubmed-meshheading:1321143-Animals, pubmed-meshheading:1321143-Azides, pubmed-meshheading:1321143-Blotting, Western, pubmed-meshheading:1321143-Chorionic Gonadotropin, pubmed-meshheading:1321143-Chromatography, DEAE-Cellulose, pubmed-meshheading:1321143-Corpus Luteum, pubmed-meshheading:1321143-Cyclic AMP, pubmed-meshheading:1321143-Cytosol, pubmed-meshheading:1321143-Enzyme Stability, pubmed-meshheading:1321143-Female, pubmed-meshheading:1321143-Forskolin, pubmed-meshheading:1321143-Half-Life, pubmed-meshheading:1321143-Kinetics, pubmed-meshheading:1321143-Macromolecular Substances, pubmed-meshheading:1321143-Methionine, pubmed-meshheading:1321143-Ovarian Follicle, pubmed-meshheading:1321143-Protein Kinases, pubmed-meshheading:1321143-RNA, Messenger, pubmed-meshheading:1321143-Rabbits
pubmed:year
1992
pubmed:articleTitle
Luteinization-associated changes in protein stability of the regulatory subunit of the type I cAMP-dependent protein kinase.
pubmed:affiliation
Department of Cellular, Molecular, and Structural Biology, Northwestern University Medical School, Chicago, Illinois 60611.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.