Linked Life Data

9819358

Source:http://linkedlifedata.com/resource/pubmed/id/9819358

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1999-2-16
pubmed:abstractText
We have previously identified and quantitated three B-type lamin isoforms present in the nuclei of mature Xenopus laevis oocytes, and in cell-free egg extracts. As Xenopus egg extracts are frequently used to analyze nuclear envelope assembly and lamina functions, we felt it was imperative that the polymerization and chromatin-binding properties of the endogenous B-type egg lamins be investigated. While we have demonstrated that soluble B-type lamins bind to chromatin, we have also observed that the polymerization of egg lamins does not require membranes or chromatin. Lamin assembly is enhanced by the addition of glycogen/glucose, or by the depletion of ATP from the extract. Moreover, the polymerization of egg cytosol lamins and their binding to demembranated sperm or chromatin assembled from naked lambda-DNA is inhibited by an ATP regeneration system. These ATP-dependent inhibitory activities can be overcome by the coaddition of glycogen to egg cytosol. We have observed that glycogen does not alter ATP levels during cytosol incubation, but rather, as glycogen-enhanced lamin polymerization is inhibited by okadaic acid, we conclude that glycogen activates protein phosphatases. Because protein phosphatase 1 (PP1) is the only phosphatase known to be specifically regulated by glycogen our data indicate that PP1 is involved in lamin polymerization. Our results show that ATP and glycogen effect lamin polymerization and chromatin binding by separate and opposing mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
111 ( Pt 24)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3675-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Chromatin binding and polymerization of the endogenous Xenopus egg lamins: the opposing effects of glycogen and ATP.
pubmed:affiliation
Division of Electron Microscopy, Biocenter of the University of W urzburg, Am Hubland, D-97074 Würzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't