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.

Single-Molecule Folding Mechanism of an EF-Hand Neuronal Calcium Sensor / Heidarsson, Petur O.; Otazo, Mariela R.; Bellucci, Luca; Mossa, Alessandro; Imparato, Alberto; Paci, Emanuele; Corni, Stefano; DI FELICE, Rosa; Kragelund, Birthe B.; Cecconi, Ciro. - In: STRUCTURE. - ISSN 0969-2126. - 21:10(2013), pp. 1812-1821. [10.1016/j.str.2013.07.022]

Single-Molecule Folding Mechanism of an EF-Hand Neuronal Calcium Sensor

BELLUCCI, LUCA;CORNI, STEFANO;DI FELICE, ROSA;CECCONI, CIRO
2013

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
21
10
1812
1821
Single-Molecule Folding Mechanism of an EF-Hand Neuronal Calcium Sensor / Heidarsson, Petur O.; Otazo, Mariela R.; Bellucci, Luca; Mossa, Alessandro; Imparato, Alberto; Paci, Emanuele; Corni, Stefano; DI FELICE, Rosa; Kragelund, Birthe B.; Cecconi, Ciro. - In: STRUCTURE. - ISSN 0969-2126. - 21:10(2013), pp. 1812-1821. [10.1016/j.str.2013.07.022]
Heidarsson, Petur O.; Otazo, Mariela R.; Bellucci, Luca; Mossa, Alessandro; Imparato, Alberto; Paci, Emanuele; Corni, Stefano; DI FELICE, Rosa; Kragel...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1070001
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