title: Muscle-specific calpain, p94, interacts with the extreme C-terminal region of connectin, a unique region flanked by two immunoglobulin C2 motifs.
abstract: Using the yeast two-hybrid system, we have recently reported that skeletal muscle-specific calpain, p94, binds specifically to connectin (or titin), a gigantic muscle elastic protein. Connectin has at least two binding sites for p94; one is at the N2-line region and the other is at the extreme C-terminus. In order to analyze the interaction between p94 and the C-terminus of connectin, we examined the C-terminal sequence of human skeletal muscle connectin. The sequence was essentially identical to that of heart muscle reported by Labeit and Kolmerer (1995, Science 270, 293-296), and the minimal binding site for p94 contained two IgC2 motifs and the intervening sequence called "M-is7." The exon encoding M-is7 is reported to be alternatively spliced depending on muscle tissues, resulting in the existence of both types of connectin with and without M-is7. However, the C-terminal region of connectin bound to p94 through M-is7. Our results suggest that the interaction between p94 and the C-terminus of skeletal muscle-type connectin is involved in tissue-specific myofibriogenesis.
authors.affiliation: Department of Molecular Biology, Institute of Molecular and Cellular Biosciences, University of Tokyo, Bunkyo-ku, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kinbara
authors.forename: H
authors.initials: H
authors.lastname: Sorimachi
authors.forename: S
authors.initials: S
authors.lastname: Ishiura
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002154:Calpain / Q000737:chemistry / Q000378:metabolism*; D003001:Cloning, Molecular; D064211:Connectin; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D064211:Connectin; D018076:DNA, Complementary; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases; D002154:Calpain; C078134:calpain p94