1. Tissue-specific interactions of TNI isoforms with other TN subunits and tropomyosins in C. elegans: the role of the C- and N-terminal extensions.
- Author
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Amin MZ, Bando T, Ruksana R, Anokye-Danso F, Takashima Y, Sakube Y, and Kagawa H
- Subjects
- Amino Acid Sequence, Animals, Caenorhabditis elegans chemistry, Molecular Sequence Data, Muscle Proteins chemistry, Muscles immunology, Organ Specificity, Pharynx immunology, Protein Interaction Mapping, Tropomyosin immunology, Troponin C chemistry, Troponin I immunology, Troponin T chemistry, Troponin T immunology, Protein Isoforms chemistry, Tropomyosin chemistry, Troponin I chemistry
- Abstract
The aim of this study is to investigate the function of the C-terminal extension of three troponin I isoforms, that are unique to the body wall muscles of Caenorhabditis elegans and to understand the molecular interactions within the TN complex between troponin I with troponin C/T, and tropomyosin. We constructed several expression vectors to generate recombinant proteins of three body wall and one pharyngeal troponin I isoforms in Escherichia coli. Protein overlay assays and Western blot analyses were performed using antibodies. We demonstrated that pharyngeal TNI-4 interacted with only the pharyngeal isoforms of troponin C/T and tropomyosin. In contrast, the body wall TNI-2 bound both the body wall and pharyngeal isoforms of these components. Similar to other invertebrates, the N-terminus of troponin I contributes to interactions with troponin C. Full-length troponin I was essential for interactions with tropomyosin isoforms. Deletion of the C-terminal extension had no direct effect on the binding of the body wall troponin I to other muscle thin filament troponin C/T and tropomyosin isoforms.
- Published
- 2007
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