Tissue-specific interactions of TNI isoforms with other TN subunits and tropomyosins in C. elegans: the role of the C- and N-terminal extensions.
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.
Amin
Md Ziaul
MZ
Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Bando
Tetsuya
T
Ruksana
Razia
R
Anokye-Danso
Frederick
F
Takashima
Yasuo
Y
Sakube
Yasuji
Y
Kagawa
Hiroaki
H
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000737:chemistry; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry; D009132:Muscles / Q000276:immunology; D009928:Organ Specificity; D010614:Pharynx / Q000276:immunology; D025941:Protein Interaction Mapping; D020033:Protein Isoforms / Q000737:chemistry*; D014335:Tropomyosin / Q000737:chemistry* / Q000276:immunology; D019209:Troponin C / Q000737:chemistry; D019210:Troponin I / Q000737:chemistry* / Q000276:immunology; D020107:Troponin T / Q000737:chemistry / Q000276:immunology
D009124:Muscle Proteins; D020033:Protein Isoforms; D014335:Tropomyosin; D019209:Troponin C; D019210:Troponin I; D020107:Troponin T