Hypertension is the most prevalent risk factor for cardiovascular diseases, present in almost 30% of adults. A key element in the control of vascular tone is the large-conductance, Ca2+-dependent K+ (BK) channel. The BK channel in vascular smooth muscle is formed by an ion-conducting α subunit and a regulatory β1 subunit, which couples local increases in intracellular Ca2+ to augmented channel activity and vascular relaxation. Our large population-based genetic epidemiological study has identified a new single-nucleotide substitution (G352A) in the β1 gene (KCNMB1), corresponding to an E65K mutation in the protein. This mutation results in a gain of function of the channel and is associated with low prevalence of moderate and severe diastolic hypertension. BK-β1E65K channels showed increased Ca2+ sensitivity, compared with wild-type channels, without changes in channel kinetics. In conclusion, the BK-β1E65K channel might offer a more efficient negative-feedback effect on vascular smooth muscle contractility, consistent with a protective effect of the K allele against the severity of diastolic hypertension.
José M. Fernández-Fernández, Marta Tomás, Esther Vázquez, Patricio Orio, Ramón Latorre, Mariano Sentí, Jaume Marrugat, Miguel A. Valverde
Title and authors | Publication | Year |
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Defining the BK channel domains required for beta1-subunit modulation
JP Morrow, SI Zakharov, G Liu, L Yang, AJ Sok, SO Marx |
Proceedings of the National Academy of Sciences | 2006 |
Structural Determinants for Functional Coupling Between the β and α Subunits in the Ca 2+ -activated K + (BK) Channel
P Orio, Y Torres, P Rojas, I Carvacho, ML Garcia, L Toro, MA Valverde, R Latorre |
The Journal of General Physiology | 2006 |
In Vivo Analysis of a Gain-of-Function Mutation in the Drosophila eag -Encoded K + Channel
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G Gessner, K Schönherr, M Soom, A Hansel, M Asim, A Baniahmad, C Derst, T Hoshi, SH Heinemann |
The Journal of Membrane Biology | 2006 |