KCNU1

This gene encodes a member of the potassium channel family of proteins. The encoded voltage-gated ion channel allows the outward flow of potassium ions during plasma membrane hyperpolarization in sperm. Opening of this channel may be regulated by calcium ion levels. Homozygous knockout mice that lack the related mouse gene exhibit male sterility. Alternative splicing results in multiple transcript variants.

Full Name

potassium channel, subfamily U, member 1

Function

Testis-specific potassium channel activated by both intracellular pH and membrane voltage that mediates export of K(+). May represent the primary spermatozoan K(+) current. In contrast to KCNMA1/SLO1, it is not activated by Ca(2+) or Mg(2+). Critical for fertility. May play an important role in sperm osmoregulation required for the acquisition of normal morphology and motility when faced with osmotic challenges, such as those experienced after mixing with seminal fluid and entry into the vagina.

Biological Process

Regulation of ion transmembrane transportIEA:UniProtKB-KW
Reproductive processManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Cell membrane

Topology

Extracellular: 1-24
Helical: 25-45
Cytoplasmic: 46-101
Helical: 102-122
Extracellular: 123-138
Helical: 139-159
Cytoplasmic: 160-163
Helical: 164-184
Extracellular: 185-188
Helical: 189-209
Cytoplasmic: 210-226
Helical: 227-247
Extracellular: 248-259
Pore-forming: 260-282
Extracellular: 283-291
Helical: 292-312
Cytoplasmic: 313-1149