Linked Life Data

17928315

Source:http://linkedlifedata.com/resource/pubmed/id/17928315

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 12
pubmed:dateCreated
2007-12-6
pubmed:abstractText
Specific mutations within the alpha-skeletal actin gene (ACTA1) result in intranuclear rod myopathy (IRM), characterized by rod-like aggregates containing actin and alpha-actinin-2 inside the nucleus of muscle cells. The mechanism leading to formation of intranuclear aggregates containing sarcomeric proteins and their impact on cell function and contribution to disease pathogenesis is unknown. In this study, we transfected muscle and non-muscle cells with mutants of alpha-skeletal actin (Val163Leu, Val163Met) associated with intranuclear rod myopathy. By live-cell imaging we demonstrate that nuclear aggregates of actin form within the nuclear compartment, rather than entering the nucleus after formation in the cytoplasm, and are highly motile and dynamic structures. Thus, the nuclear environment supports the polymerization of actin and the movement and coalescence of the polymerized actin into larger structures. We show that the organization of actin within these aggregates is influenced by the binding of alpha-actinin, and that alpha-actinin is normally present in the nucleus of muscle and non-muscle cells. Furthermore, we demonstrate that, under conditions of cell stress (cytoskeletal disruption and ATP depletion), WT skeletal actin forms aggregates within the nucleus that are similar in morphology to those formed by the mutant actin, suggesting a common pathogenic mechanism for aggregate formation. Finally, we show that the presence of intranuclear actin aggregates significantly decreases the mitotic index and hence impacts on the function of the cell. Intranuclear aggregates thus likely contribute to the pathogenesis of muscle weakness in intranuclear rod myopathy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1460-2156
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3275-84
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Mechanisms underlying intranuclear rod formation.
pubmed:affiliation
Institute for Neuromuscular Research, Children's Hospital at Westmead, NSW, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't