cAMP signaling in the brain mediates several higher order neural processes. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels directly bind cAMP through their cytoplasmic cyclic nucleotide binding domain (CNBD), thus playing a unique role in brain function. Neuronal HCN channels are also regulated by tetratricopeptide repeat-containing Rab8b interacting protein (TRIP8b), an auxiliary subunit that antagonizes the effects of cAMP by interacting with the channel CNBD. To unravel the molecular mechanisms underlying the dual regulation of HCN channel activity by cAMP/TRIP8b, we determined the NMR solution structure of the HCN2 channel CNBD in the cAMP-free form and mapped on it the TRIP8b interaction site. We reconstruct here the full conformational changes induced by cAMP binding to the HCN channel CNBD. Our results show that TRIP8b does not compete with cAMP for the same binding region; rather, it exerts its inhibitory action through an allosteric mechanism, preventing the cAMP-induced conformational changes in the HCN channel CNBD.
Structural basis for the mutual antagonism of cAMP and TRIP8b in regulating HCN channel function / A. Saponaro, S.R. Pauleta, F. Cantini, M. Matzapetakis, C. Hammann, C. Donadoni, L. Hu, G. Thiel, L. Banci, B. Santoro, A. Moroni. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - 111:40(2014 Oct 07), pp. 14577-14582.
|Titolo:||Structural basis for the mutual antagonism of cAMP and TRIP8b in regulating HCN channel function|
SAPONARO, ANDREA COSIMO (Primo)
MORONI, ANNA (Ultimo)
|Settore Scientifico Disciplinare:||Settore BIO/04 - Fisiologia Vegetale|
|Data di pubblicazione:||7-ott-2014|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1073/pnas.1410389111|
|Appare nelle tipologie:||01 - Articolo su periodico|