Acute Activation of Maxi-K Channels (hSlo) by Estradiol Binding to the 
Subunit
Miguel A. Valverde,
1*
Patricio Rojas,
2
Julio Amigo,
2
Diego Cosmelli,
2
Patricio Orio,
2
Maria I. Bahamonde,
2
Giovanni E. Mann,
4
Cecilia Vergara,
2
Ramon Latorre
23
Maxi-K channels consist of a pore-forming 
subunit and a
regulatory 
subunit, which confers the channel with a higher
Ca2+ sensitivity. Estradiol bound to the subunit and
activated the Maxi-K channel (hSlo) only when both and
subunits were present. This activation was independent of the
generation of intracellular signals and could be triggered by estradiol
conjugated to a membrane-impenetrable carrier protein. This study
documents the direct interaction of a hormone with a voltage-gated
channel subunit and provides the molecular mechanism for the modulation
of vascular smooth muscle Maxi-K channels by estrogens.
1 Departament de Ciències Experimentals i de la
Salut, Universidad Pompeu Fabra, C/Doctor Aiguader 80, 08003 Barcelona,
Spain.
2 Departmento de Biología, Facultad de
Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and
Centro de Estudios Cientificos de Santiago, Casilla 16443, Santiago 9, Chile.
3 Department of Anesthesiology, University of
California Los Angeles, Los Angeles, CA 90095-1778, USA.
4 Centre for Cardiovascular Biology and Medicine, School of
Biomedical Sciences, King's College London, London SE1 9RT, UK.
*
To whom correspondence should be addressed. E-mail:
miguel.valverde{at}cexs.upf.es
