The SLO3 sperm-specific potassium channel plays a vital role in male fertility.
Here we show a unique example of male infertility conferred by a gene knockout of the sperm-specific, pH-dependent SLO3 potassium channel. In striking contrast to wild-type sperm which undergo membrane hyperpolarization during capacitation, we found that SLO3 mutant sperm undergo membrane depolarization. Several defects in SLO3 mutant sperm are evident under capacitating conditions, including impaired motility, a bent "hairpin" shape, and failure to undergo the acrosome reaction (AR). The failure of AR is rescued by valinomycin which hyperpolarizes mutant sperm. Thus SLO3 is the principal potassium channel responsible for capacitation-induced hyperpolarization, and membrane hyperpolarization is crucial to the AR.
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA. santic@pcg.wustl.edu
Celia M
CM
Santi
Pablo
P
Martínez-López
José Luis
JL
de la Vega-Beltrán
Alice
A
Butler
Arturo
A
Alisio
Alberto
A
Darszon
Lawrence
L
Salkoff
D020101:Acrosome Reaction / Q000235:genetics / Q000502:physiology; D000818:Animals; D015153:Blotting, Western; D004594:Electrophysiology; D005260:Female; D005307:Fertilization in Vitro; D007248:Infertility, Male / Q000235:genetics* / Q000378:metabolism; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013075:Sperm Capacitation / Q000235:genetics / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism / Q000473:pathology
C110627:Kcnu1 protein, mouse; D051036:Large-Conductance Calcium-Activated Potassium Channels