Towards Understanding the Molecular Bases of Stretch Activation: A Structural comparison of the Two Troponin C Isoforms of Lethocerus.
File(s)
Published version
Author(s)
Sanfelice, D
Sanz-Hernandez, M
De Simone, A
Bullard, B
Pastore, A
Type
Journal Article
Abstract
Muscles are usually activated by calcium binding to the calcium-sensory protein troponin-C, which is one of the three components of the troponin complex. However, in cardiac and insect flight muscle (IFM) activation is also provided by mechanical stress. Little is known about the molecular bases of this calcium-independent activation. In Lethocerus, a giant water bug often used as a model system thanks to the big size of its muscle fibers, there are two troponin-C isoforms, named F1 and F2, which seem to have very distinct roles and mechanical properties. It has been suggested that this behaviour can be explained either by differences in structural features, or by differences in the interactions with other proteins. Here, we have compared the structural and dynamic properties of the two proteins and shown that the two proteins have intrinsically different behaviours. We also mapped the interactions of the F2 isoform with peptides spanning the sequence of its natural partner, troponin I. Our data allowed us to build a model of the troponin complex and may eventually help understanding the specialised function of the F1 isoform and the molecular mechanism of stretch activation.
Date Issued
2016-05-20
Date Acceptance
2016-05-18
Citation
Journal of Biological Chemistry, 2016, 291, pp.16090-16099
ISSN
1083-351X
Publisher
American Society for Biochemistry and Molecular Biology
Start Page
16090
End Page
16099
Journal / Book Title
Journal of Biological Chemistry
Volume
291
Copyright Statement
Final version free via Creative Commons CC-BY license
Sponsor
British Heart Foundation
Identifier
PII: M116.726646
Grant Number
PG/14/93/31237
Subjects
muscle
protein-protein interaction
stress
structural biology
structure-function
Publication Status
Published