EF-hand calcium sensors respond structurally to changes in intracellular Ca2+ concentration, triggering diverse cellular responses and resulting in broad interactomes. Despite impressive advances in decoding their structure-function relationships, the folding mechanism of neuronal calcium sensors is still elusive. We used single-molecule optical tweezers to study the folding mechanism of the human neuronal calcium sensor 1 (NCS1). Two intermediate structures induced by Ca2+ binding to the EF-hands were observed during refolding. The complete folding of the C domain is obligatory for the folding of the N domain, showing striking interdomain dependence. Molecular dynamics results reveal the atomistic details of the unfolding process and rationalize the different domain stabilities during mechanical unfolding. Through constant-force experiments and hidden Markov model analysis, the free energy landscape of the protein was reconstructed. Our results emphasize that NCS1 has evolved a remarkable complex interdomain cooperativity and a fundamentally different folding mechanism compared to structurally related proteins. © 2013 Elsevier Ltd.
Titolo: | Single-molecule folding mechanism of an EF-hand neuronal calcium sensor | |
Autore/i: | Heidarsson P. O.; Otazo M. R.; Bellucci L.; Mossa A.; Imparato A.; Paci E.; Corni S.; Di Felice R.; Kragelund B. B.; Cecconi C. | |
Autore/i Unibo: | ||
Anno: | 2013 | |
Rivista: | ||
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.str.2013.07.022 | |
Abstract: | EF-hand calcium sensors respond structurally to changes in intracellular Ca2+ concentration, triggering diverse cellular responses and resulting in broad interactomes. Despite impressive advances in decoding their structure-function relationships, the folding mechanism of neuronal calcium sensors is still elusive. We used single-molecule optical tweezers to study the folding mechanism of the human neuronal calcium sensor 1 (NCS1). Two intermediate structures induced by Ca2+ binding to the EF-hands were observed during refolding. The complete folding of the C domain is obligatory for the folding of the N domain, showing striking interdomain dependence. Molecular dynamics results reveal the atomistic details of the unfolding process and rationalize the different domain stabilities during mechanical unfolding. Through constant-force experiments and hidden Markov model analysis, the free energy landscape of the protein was reconstructed. Our results emphasize that NCS1 has evolved a remarkable complex interdomain cooperativity and a fundamentally different folding mechanism compared to structurally related proteins. © 2013 Elsevier Ltd. | |
Data stato definitivo: | 2022-05-12T17:12:22Z | |
Appare nelle tipologie: | 1.01 Articolo in rivista |