title: Chicken breast muscle connectin: passive tension and I-band region primary structure.
abstract: We performed cDNA cloning of chicken breast muscle connectin. Together with previous results, our analysis elucidated a 24.2 kb sequence encoding the amino terminus of the protein. This corresponded to the I-band region of the skeletal muscle sarcomere, which is involved in extension and contraction between the Z-line and the A-I junction. There were fewer middle immunoglobulin domains and amino acid residues in the PEVK segment of chicken breast muscle connectin than in human skeletal muscle connectin, but more than in human cardiac muscle connectin. We measured passive tension generation by stretching mechanically skinned myofibril bundles. This revealed that appreciable tension development in chicken breast muscle began at longer sarcomere spacings than in rabbit cardiac muscle, but at shorter spacings than in rabbit psoas and soleus muscles. We suggest that the chicken breast muscle sarcomere remains in a relatively extended state even in unstrained sarcomeres. This would explain why chicken breast muscle does not extend under force to the same degree as rabbit psoas and soleus muscles.
authors.affiliation: Department of Biology, Faculty of Science, Chiba University, Chiba 263-8522, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Noguchi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Takemori
authors.forename: Junpei
authors.initials: J
authors.lastname: Kajiwara
authors.forename: Masako
authors.initials: M
authors.lastname: Kimura
authors.forename: Koscak
authors.initials: K
authors.lastname: Maruyama
authors.forename: Sumiko
authors.initials: S
authors.lastname: Kimura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D064211:Connectin; D006801:Humans; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry* / Q000502:physiology; D009129:Muscle Tonus; D018482:Muscle, Skeletal / Q000737:chemistry / Q000502:physiology; D009132:Muscles / Q000737:chemistry* / Q000502:physiology; D011494:Protein Kinases / Q000737:chemistry* / Q000502:physiology; D011817:Rabbits; D012518:Sarcomeres / Q000737:chemistry / Q000502:physiology; D016415:Sequence Alignment; D017385:Sequence Homology
chemical_list: D064211:Connectin; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases