Intermediate filaments, composed of desmin and of keratins, play important roles in linking contractile elements to each other and to the sarcolemma in striated muscle. We examined the contractile properties and morphology of fast-twitch skeletal muscle from mice lacking keratin 19. Tibialis anterior muscles of keratin-19-null mice showed a small but significant decrease in mean fiber diameter and in the specific force of tetanic contraction, as well as increased plasma creatine kinase levels. Costameres at the sarcolemma of keratin-19-null muscle, visualized with antibodies against spectrin or dystrophin, were disrupted and the sarcolemma was separated from adjacent myofibrils by a large gap in which mitochondria accumulated. The costameric dystrophin-dystroglycan complex, which co-purified with gamma-actin, keratin 8 and keratin 19 from striated muscles of wild-type mice, co-purified with gamma-actin but not keratin 8 in the mutant. Our results suggest that keratin 19 in fast-twitch skeletal muscle helps organize costameres and links them to the contractile apparatus, and that the absence of keratin 19 disrupts these structures, resulting in loss of contractile force, altered distribution of mitochondria and mild myopathy. This is the first demonstration of a mammalian phenotype associated with a genetic perturbation of keratin 19.
Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization. Publishing Authors By Initials
Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization. Journal Published:
PUBLICATION TYPE: Journal Article
Journal: Journal of cell science
VOLUME: 120
Page Numbers: 3999-4008
Journal Abbreviation: J. Cell. Sci.
ISSN: 0021-9533
DAY: 30
MONTH: 10
YEAR: 2007
Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization. Information
Number of References:
LANGUAGE: eng
NlmUniqueID: 52457
Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization. Keywords Mesh Terms:
KEYWORDS:
MESH TERMS:
Chemical & Substance for Abstract: Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization. Information
Substance Name:
Registry Number:
Grant and Affiliation Information for Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization.
AFFILIATION: Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Country: England
AGENCY:
GRANT:
ACRONYM:
MEDLINETA: J Cell Sci
REFSOURCE:
DATABASENAME:
ACCESSION NUMBER:
Number Hits: 0
Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization Related Publications