Complete primary structure and tissue expression of chicken pectoralis M-protein.
M-Protein (165 kDa) is a structural constituent of myofibrillar M-band in striated muscle. We generated a monoclonal antibody which recognized a 165-kDa protein from chicken pectoralis muscle in immunoblot analysis and stained the M-band under immunofluorescence microscopy. By screening a lambda gt11 cDNA library from chicken embryonic pectoralis muscle with this antibody, we isolated a cDNA clone encoding the M-protein. Northern blot analysis showed that M-protein mRNA is expressed in pectoralis and cardiac muscle but not in gizzard smooth muscle or non-muscle tissues. Moreover, the anterior latissimus dorsi muscle, which consists almost exclusively of slow fiber types, contains no detectable levels of the mRNA. The full-length cDNA sequence predicted a 1,450-amino acid polypeptide with a calculated molecular weight of 163 x 10(3). The encoded protein contains several copies of two different repetitive motifs: five copies of fibronectin type III repeats are in the middle part of the predicted molecule, and two and four copies of the immunoglobulin C2-type repeats are located toward the NH2-terminal and COOH-terminal regions, respectively. This indicates that M-protein, along with other thick filament-associated proteins such as C-protein, twichin, and titin, belongs to the superfamily of cytoskeletal proteins with immunoglobulin/fibronectin repeats.
Noguchi
J
J
Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Yanagisawa
M
M
Imamura
M
M
Kasuya
Y
Y
Sakurai
T
T
Tanaka
T
T
Masaki
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002645:Chickens; D003001:Cloning, Molecular; D064211:Connectin; D004247:DNA; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D010369:Pectoralis Muscles / Q000737:chemistry*; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
D064211:Connectin; D009124:Muscle Proteins; D012333:RNA, Messenger; D004247:DNA