Beta-synemin localizes to regions of high stress in human skeletal myofibers.
Synemin is an intermediate filament protein shown previously to interact with alpha-dystrobrevin and desmin. Immunoblot analysis detects a beta-synemin protein of 170 kDa in human skeletal muscle and an alpha-synemin protein of 225 kDa in monkey brain. Low-resolution immunohistochemical analysis localizes beta-synemin within muscle along the sarcolemma, whereas confocal microscopic analysis further refines localization to the costamere and muscle Z-lines. In addition to these locations, beta-synemin is also enriched at the neuromuscular and myotendinous junctions, other regions that undergo high stress during myofiber contraction. Based on its localization and its expression pattern, it is proposed that beta-synemin functions as a structural protein involved in maintaining muscle integrity through its interactions with alpha-dystrobrevin, desmin, and other structural proteins.
Department of Neurology, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma 371-8511, Japan. mizunoy@med.gunma-u.ac.jp
Yuji
Y
Mizuno
Jeffrey R
JR
Guyon
Simon C
SC
Watkins
Kazuyuki
K
Mizushima
Toshikuni
T
Sasaoka
Michihiro
M
Imamura
Louis M
LM
Kunkel
Koichi
K
Okamoto
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D005260:Female; D000882:Haplorhini; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins; D051379:Mice; D018101:Mice, Inbred mdx; D008969:Molecular Sequence Data; D018485:Muscle Fibers, Skeletal / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D009124:Muscle Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism / Q000503:physiopathology*; D013045:Species Specificity; D013312:Stress, Physiological / Q000378:metabolism* / Q000503:physiopathology*
D007381:Intermediate Filament Proteins; D009124:Muscle Proteins; C430456:desmuslin