Biomaterial Database

The Ca2+-activated K+ current of human sperm is mediated by Slo3. 2014

Christoph Brenker, and Yu Zhou, and Astrid Müller, and Fabio Andres Echeverry, and Christian Trötschel, and Ansgar Poetsch, and Xiao-Ming Xia, and Wolfgang Bönigk, and Christopher J Lingle, and U Benjamin Kaupp, and Timo Strünker

Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany.

Sperm are equipped with a unique set of ion channels that orchestrate fertilization. In mouse sperm, the principal K(+) current (IKSper) is carried by the Slo3 channel, which sets the membrane potential (Vm) in a strongly pHi-dependent manner. Here, we show that IKSper in human sperm is activated weakly by pHi and more strongly by Ca(2+). Correspondingly, Vm is strongly regulated by Ca(2+) and less so by pHi. We find that inhibitors of Slo3 suppress human IKSper, and we identify the Slo3 protein in the flagellum of human sperm. Moreover, heterologously expressed human Slo3, but not mouse Slo3, is activated by Ca(2+) rather than by alkaline pHi; current-voltage relations of human Slo3 and human IKSper are similar. We conclude that Slo3 represents the principal K(+) channel in human sperm that carries the Ca(2+)-activated IKSper current. We propose that, in human sperm, the progesterone-evoked Ca(2+) influx carried by voltage-gated CatSper channels is limited by Ca(2+)-controlled hyperpolarization via Slo3. DOI: http://dx.doi.org/10.7554/eLife.01438.001.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D005407	Flagella	A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Flagellum
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D013094	Spermatozoa	Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.	Sperm,Spermatozoon,X-Bearing Sperm,X-Chromosome-Bearing Sperm,Y-Bearing Sperm,Y-Chromosome-Bearing Sperm,Sperm, X-Bearing,Sperm, X-Chromosome-Bearing,Sperm, Y-Bearing,Sperm, Y-Chromosome-Bearing,Sperms, X-Bearing,Sperms, X-Chromosome-Bearing,Sperms, Y-Bearing,Sperms, Y-Chromosome-Bearing,X Bearing Sperm,X Chromosome Bearing Sperm,X-Bearing Sperms,X-Chromosome-Bearing Sperms,Y Bearing Sperm,Y Chromosome Bearing Sperm,Y-Bearing Sperms,Y-Chromosome-Bearing Sperms
D051036	Large-Conductance Calcium-Activated Potassium Channels	A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.	BK Channel,Big K Channel,Large-Conductance Calcium-Activated Potassium Channel,Maxi K Channel,Maxi-K Channel,MaxiK Channel,BK Channels,Big K Channels,Maxi-K Channels,MaxiK Channels,Channel, BK,Channel, Big K,Channel, Maxi K,Channel, Maxi-K,Channel, MaxiK,K Channel, Big,K Channel, Maxi,Large Conductance Calcium Activated Potassium Channel,Large Conductance Calcium Activated Potassium Channels,Maxi K Channels
D051037	Large-Conductance Calcium-Activated Potassium Channel alpha Subunits	The pore-forming subunits of large-conductance calcium-activated potassium channels. They form tetramers in CELL MEMBRANES.	Large-Conductance Calcium-Activated Potassium Channels, alpha Subunit,MaxiK Channel alpha Subunit,Large Conductance Calcium Activated Potassium Channel alpha Subunits,Large Conductance Calcium Activated Potassium Channels, alpha Subunit
D024642	Potassium Channels, Voltage-Gated	Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.	Voltage-Gated Potassium Channels,Kv Potassium Channels,Potassium Channel, Voltage-Gated,Voltage-Gated K+ Channels,Voltage-Gated Potassium Channel,K+ Channels, Voltage-Gated,Potassium Channel, Voltage Gated,Potassium Channels, Kv,Potassium Channels, Voltage Gated,Voltage Gated K+ Channels,Voltage Gated Potassium Channel,Voltage Gated Potassium Channels