Linked Life Data

9612226

Source:http://linkedlifedata.com/resource/pubmed/id/9612226

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1998-7-1
pubmed:abstractText
We previously demonstrated that subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial subfractions import proteins at different rates. This study was undertaken to investigate 1) whether protein import is altered by chronic contractile activity, which induces mitochondrial biogenesis, and 2) whether these two subfractions adapt similarly. Using electrical stimulation (10 Hz, 3 h/day for 7 and 14 days) to induce contractile activity, we observed that malate dehydrogenase import into the matrix of the SS and IMF mitochondia isolated from stimulated muscle was significantly increased by 1.4-to 1.7-fold, although the pattern of increase differed for each subfraction. This acceleration of import may be mitochondrial compartment specific, since the import of Bcl-2 into the outer membrane was not affected. Contractile activity also modified the mitochondrial content of proteins comprising the import machinery, as evident from increases in the levels of the intramitochondrial chaperone mtHSP70 as well as the outer membrane import receptor Tom20 in SS and IMF mitochondria. Addition of cytosol isolated from stimulated or control muscles to the import reaction resulted in similar twofold increases in the ability of mitochondria to import malate dehydrogenase, despite elevations in the concentration of mitochondrial import-stimulating factor within the cytosol of chronically stimulated muscle. These results suggest that chronic contractile activity modifies the extra- and intramitochondrial environments in a fashion that favors the acceleration of precursor protein import into the matrix of the organelle. This increase in protein import is likely an important adaptation in the overall process of mitochondrial biogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1380-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9612226-Adaptation, Physiological, pubmed-meshheading:9612226-Animals, pubmed-meshheading:9612226-Cytosol, pubmed-meshheading:9612226-Electric Stimulation, pubmed-meshheading:9612226-HSP70 Heat-Shock Proteins, pubmed-meshheading:9612226-Malate Dehydrogenase, pubmed-meshheading:9612226-Male, pubmed-meshheading:9612226-Membrane Proteins, pubmed-meshheading:9612226-Membrane Transport Proteins, pubmed-meshheading:9612226-Mitochondria, Muscle, pubmed-meshheading:9612226-Molecular Chaperones, pubmed-meshheading:9612226-Muscle Contraction, pubmed-meshheading:9612226-Muscle Proteins, pubmed-meshheading:9612226-Myofibrils, pubmed-meshheading:9612226-Proto-Oncogene Proteins c-bcl-2, pubmed-meshheading:9612226-RNA, Messenger, pubmed-meshheading:9612226-Rats, pubmed-meshheading:9612226-Rats, Sprague-Dawley, pubmed-meshheading:9612226-Receptors, Cell Surface, pubmed-meshheading:9612226-Sarcolemma
pubmed:year
1998
pubmed:articleTitle
Contractile activity-induced adaptations in the mitochondrial protein import system.
pubmed:affiliation
Department of Biology, York University, Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't