Linked Life Data

12646563

Source:http://linkedlifedata.com/resource/pubmed/id/12646563

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2003-5-19
pubmed:abstractText
The human homologue of yeast Rrn3, a 72-kDa protein, is essential for ribosomal DNA (rDNA) transcription. Although the importance of Rrn3 function in rDNA transcription is well established, its mechanism of action has not been determined. It has been suggested that the phosphorylation of either yeast RNA polymerase I or mammalian Rrn3 regulates the formation of RNA polymerase I.Rrn3 complexes that can interact with the committed template. These and other reported differences would have implications with respect to the mechanism by which Rrn3 functions in transcription. For example, in the yeast rDNA transcription system, Rrn3 might function catalytically, but in the mammalian system it might function stoichiometrically. Thus, we examined the question as to whether Rrn3 functions catalytically or stoichiometrically. We report that mammalian Rrn3 becomes the limiting factor as transcription reactions proceed. Moreover, we demonstrate that Rrn3 is inactivated during the transcription reactions. For example, Rrn3 isolated from a reaction that had undergone transcription cannot activate transcription in a subsequent reaction. We also show that this inactivated Rrn3 not only dissociates from RNA polymerase I, but is not capable of forming a stable complex with RNA polymerase I. Our results indicate that Rrn3 functions stoichiometrically in rDNA transcription and that its ability to associate with RNA polymerase I is lost upon transcription.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18953-9
pubmed:dateRevised
2004-12-3
pubmed:meshHeading
pubmed-meshheading:12646563-Animals, pubmed-meshheading:12646563-Blotting, Western, pubmed-meshheading:12646563-Cell Line, pubmed-meshheading:12646563-Cycloheximide, pubmed-meshheading:12646563-DNA, Ribosomal, pubmed-meshheading:12646563-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:12646563-Gene Expression, pubmed-meshheading:12646563-Immunosorbent Techniques, pubmed-meshheading:12646563-Phosphorylation, pubmed-meshheading:12646563-Pol1 Transcription Initiation Complex Proteins, pubmed-meshheading:12646563-Protein Synthesis Inhibitors, pubmed-meshheading:12646563-RNA Polymerase I, pubmed-meshheading:12646563-Rats, pubmed-meshheading:12646563-Recombinant Proteins, pubmed-meshheading:12646563-Spodoptera, pubmed-meshheading:12646563-Transcription, Genetic, pubmed-meshheading:12646563-Transcription Factors
pubmed:year
2003
pubmed:articleTitle
Rrn3 becomes inactivated in the process of ribosomal DNA transcription.
pubmed:affiliation
Sigfried and Janet Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania 17821, USA.
pubmed:publicationType
Journal Article