Linked Life Data

1993671

Source:http://linkedlifedata.com/resource/pubmed/id/1993671

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1991-3-20
pubmed:abstractText
We have demonstrated previously that the carboxyl- and amino-terminal propeptides of type I procollagen can inhibit procollagen synthesis by specifically decreasing procollagen mRNA levels. The objective of the present experiments was to determine the mechanism by which propeptides cause these pretranslational effects. IMR-90 fibroblasts were exposed to medium containing carboxyl-terminal propeptide of type I procollagen, and nuclear run-off assays were performed by hybridization to a specific alpha 1 chain type I procollagen cDNA probe. Specific type I procollagen transcription rates were found to be decreased by 50% in the presence of 75 nM carboxyl-terminal propeptide compared with control (untreated) cells. Total cellular transcription rates as well as beta-actin mRNA rates were not affected significantly by any concentration of carboxyl-terminal propeptide. Propeptide radiolabeled with 125I was found to be taken up by cultured cells. Furthermore, exogenous carboxyl-terminal propeptide levels increased in the cytosolic compartment and eventually reached a steady-state level of 18 +/- 2 pmol/g cell protein by 30 min. Of particular interest was the finding that levels of radiolabeled carboxyl-terminal propeptide were also detected in the nuclear fraction and increased with time, reaching a plateau after 60 min of incubation. Incubation of nuclei from IMR-90 cells in medium containing varying concentrations of carboxyl-terminal propeptide resulted in nuclear transcription rates that were decreased by 40% compared with untreated controls. beta-Actin nuclear message levels remained unchanged under identical conditions. We conclude that carboxyl-terminal propeptide of type I procollagen can be internalized and become associated with the nuclear compartment. This suggests a feedback regulatory role on procollagen synthesis by a direct effect on procollagen gene transcription.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2983-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Propeptide-mediated regulation of procollagen synthesis in IMR-90 human lung fibroblast cell cultures. Evidence for transcriptional control.
pubmed:affiliation
Department of Medicine, University of Connecticut School of Medicine, Farmington 06030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't