Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1997-12-29
pubmed:abstractText
Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) is a bifunctional protein containing two enzymes that act sequentially to catalyze the conversion of glycine-extended peptides into COOH-terminal amidated peptides. We have previously shown that PAM messenger RNA (mRNA) levels in the anterior pituitary of intact cycling adult female rats showed changes inversely related to the physiological variations of plasma estrogen levels during the estrous cycle. Chronic treatment of ovariectomized (OVX) rats with 17beta-estradiol was accompanied by a 4.5 +/- 0.5-fold decrease in total PAM mRNA and a 2-fold decrease in PAM activity in the anterior pituitary gland. To investigate the cellular site at which 17beta-estradiol acts to affect the PAM mRNA, we made parallel measurements of the relative levels of PAM mRNA and nuclear precursor RNA and the relative rate of gene transcription after treatments designed to alter the estrogen status. The transcription rate experiments indicated that these 17beta-estradiol effects were not due to reduced PAM gene activity, suggesting that a posttranscriptional mechanism was involved. The most common mechanism of posttranscriptional regulation affects cytoplasmic mRNA stability. Primary rat pituitary cell cultures from OVX and OVX-17beta-estradiol-treated rats in the presence of actinomycin D showed that 17beta-estradiol treatment decreased the half-life of PAM mRNA from 15-16 h to 8-9 h. There was no effect of 17beta-estradiol on PAM mRNA poly(A) tail length or site of polyadenylation. However, in this study the down-regulation of PAM was identified as a nuclear event. Analysis of nuclear RNA with probes specific for PAM intron sequences shows that decreased PAM expression after 17beta-estradiol treatment was largely due to intranuclear destabilization of the primary transcript. The levels of nuclear precursor RNA were decreased roughly 5- to 6-fold in OVX + 17beta-estradiol compared with OVX rats. The decrease in PAM mRNA is blocked by cycloheximide, indicating that its requires new protein synthesis. Mechanisms that would generate such an effect include altered stability of unprocessed message in the nucleus. The proportional changes observed in the nuclear precursor and mRNA levels suggest that the site of control is at the level of stability of the nuclear precursor RNA for PAM mRNA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5256-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9389509-Animals, pubmed-meshheading:9389509-Cell Nucleus, pubmed-meshheading:9389509-Culture Techniques, pubmed-meshheading:9389509-Cytoplasm, pubmed-meshheading:9389509-Drug Stability, pubmed-meshheading:9389509-Estradiol, pubmed-meshheading:9389509-Estrogens, pubmed-meshheading:9389509-Female, pubmed-meshheading:9389509-Half-Life, pubmed-meshheading:9389509-Mixed Function Oxygenases, pubmed-meshheading:9389509-Multienzyme Complexes, pubmed-meshheading:9389509-Ovariectomy, pubmed-meshheading:9389509-Pituitary Gland, Anterior, pubmed-meshheading:9389509-Poly A, pubmed-meshheading:9389509-Protein Processing, Post-Translational, pubmed-meshheading:9389509-RNA, Messenger, pubmed-meshheading:9389509-RNA Precursors, pubmed-meshheading:9389509-Rats, pubmed-meshheading:9389509-Rats, Sprague-Dawley, pubmed-meshheading:9389509-Transcription, Genetic
pubmed:year
1997
pubmed:articleTitle
Estrogen regulation of peptidylglycine alpha-amidating monooxygenase messenger ribonucleic acid levels by a nuclear posttranscriptional event.
pubmed:affiliation
INSERM U297, Institut Federatif de Recherche Jean Roche, Faculté de Médecine Nord, Marseille, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't