Linked Life Data

2453294

Source:http://linkedlifedata.com/resource/pubmed/id/2453294

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1988-7-8
pubmed:abstractText
The two major proteins in the I-bands of skeletal muscle, actin and tropomyosin, were each labeled with fluorescent dyes and microinjected into cultured cardiac myocytes and skeletal muscle myotubes. Actin was incorporated along the entire length of the I-band in both types of muscle cells. In the myotubes, the incorporation was uniform, whereas in cardiac myocytes twice as much actin was incorporated in the Z-bands as in any other area of the I-band. Labeled tropomyosin that had been prepared from skeletal or smooth muscle was incorporated in a doublet in the I-band with an absence of incorporation in the Z-band. Tropomyosin prepared from brain was incorporated in a similar pattern in the I-bands of cardiac myocytes but was not incorporated in myotubes. These results in living muscle cells contrast with the patterns obtained when labeled actin and tropomyosin are added to isolated myofibrils. Labeled tropomyosins do not bind to any region of the isolated myofibrils, and labeled actin binds to A-bands. Thus, only living skeletal and cardiac muscle cells incorporate exogenous actin and tropomyosin in patterns expected from their known myofibrillar localization. These experiments demonstrate that in contrast to the isolated myofibrils, myofibrils in living cells are dynamic structures that are able to exchange actin and tropomyosin molecules for corresponding labeled molecules. The known overlap of actin filaments in cardiac Z-bands but not in skeletal muscle Z-bands accounts for the different patterns of actin incorporation in these cells. The ability of cardiac myocytes and non-muscle cells but not skeletal myotubes to incorporate brain tropomyosin may reflect differences in the relative actin-binding affinities of non-muscle tropomyosin and the respective native tropomyosins. The implications of these results for myofibrillogenesis are presented.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0045-6039
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Incorporation of fluorescently labeled actin and tropomyosin into muscle cells.
pubmed:affiliation
Department of Anatomy, University of Pennsylvania, School of Medicine, Philadelphia 19104-6058.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.