Periodic binding of troponin C.I and troponin I to tropomyosin-actin filaments.
We investigated the distribution of troponin C.I and troponin I along tropomyosin-actin filaments by immunoelectron microscopy and found that anti-troponin I antibody formed transverse striations at 38 nm intervals along the bundle of filaments of both troponin C.I-tropomyosin-actin and troponin I-tropomyosin-actin. Since the length of 38 nm corresponds to the repeating period of filamentous tropomyosin along actin double strands, the present study indicates that troponin I is located at a specific region of each tropomyosin, suggesting that a specific interaction between troponin I and tropomyosin is involved in determining the periodic distribution of troponin I along tropomyosin-actin filaments.
Ohtsuki
Iwao
I
Department of Pharmacology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan. iohtsuki@po1.dti2.ne.jp
Shiraishi
Fumie
F
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D016253:Microscopy, Immunoelectron; D018482:Muscle, Skeletal / Q000378:metabolism; D011485:Protein Binding; D021122:Protein Subunits; D011817:Rabbits; D014335:Tropomyosin / Q000737:chemistry / Q000378:metabolism*; D019209:Troponin C / Q000737:chemistry / Q000378:metabolism*; D019210:Troponin I / Q000737:chemistry / Q000378:metabolism*
D000199:Actins; D021122:Protein Subunits; D014335:Tropomyosin; D019209:Troponin C; D019210:Troponin I; D002118:Calcium