Acute activation of Maxi-K channels (hSlo) by estradiol binding to the beta subunit.
Maxi-K channels consist of a pore-forming alpha subunit and a regulatory beta subunit, which confers the channel with a higher Ca(2+) sensitivity. Estradiol bound to the beta subunit and activated the Maxi-K channel (hSlo) only when both alpha and beta 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.
Valverde
M A
MA
Departament de Ciències Experimentals i de la Salut, Universidad Pompeu Fabra, C/Doctor Aiguader 80, 08003 Barcelona, Spain. miguel.valverde@cexs.upf.es
Rojas
P
P
Amigo
J
J
Cosmelli
D
D
Orio
P
P
Bahamonde
M I
MI
Mann
G E
GE
Vergara
C
C
Latorre
R
R
D000818:Animals; D002417:Cattle; D002460:Cell Line; D004594:Electrophysiology; D004958:Estradiol / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000378:metabolism*; D024681:Potassium Channels, Calcium-Activated; D011485:Protein Binding; D012333:RNA, Messenger; D051381:Rats; D014982:Xenopus laevis
C494841:KCNMA1 protein, human; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger; D004958:Estradiol