Regulation of ion balance in spermatozoa has been shown to be essential for sperm motility and fertility. Control intracellular levels requires the function distinct ion-transport mechanisms at cell plasma membrane. Active Na + K exchange is under control Na,K-ATPase. Two molecular variants catalytic subunit Na,K-ATPase, α1 α4, coexist sperm. These isoforms exhibit different biochemical properties; however, their fertility unknown. In this work, we show that Na,K-ATPase α4 Knockout male mice...

FYNkinase is highly expressed in the testis and has been implicated sperm function, yet specific roles for this kinase somatic germ cells have not defined. The purpose of present investigation was to identify aspects spermatogenesis, spermiation, or fertilizing capacity that required FYN normal reproductive function. Matings between Fyn-null males wild-type females resulted litter sizes, despite fact exhibited reduced epididymal size count. Morphological analysis revealed a high frequency...

In the rat, Na,K-ATPase α4 isoform exhibits unique enzymatic characteristics and is important for sperm motility. this work, we studied expression, localization function of in human spermatozoa. We show two catalytically active α polypeptides with different ouabain affinity identified expression α1, α4, β1 β3 isoforms gametes. addition, presented Na,K-ATPases composed α4β1 α4β3. Kinetic analysis these isozymes produced insect cells showed that, compared α1β1, α4β3 exhibit higher Na+ lower K+...

Different isoforms of the sodium/potassium adenosinetriphosphatase (Na,K-ATPase) α and β subunits have been identified in mammals. The association various polypeptides results distinct Na,K-ATPase isozymes with unique enzymatic properties. We studied function α4 isoform Sf-9 cells using recombinant baculoviruses. When Na pump β1 subunit are coexpressed cells, activity is induced. This reflected by a ouabain-sensitive hydrolysis ATP, Na+-dependent, K+-sensitive, ouabain-inhibitable...

While the function of ubiquitous Na,K-ATPase α1 subunit has been well documented, role sperm-specific α4 isoform this ion transporter is less known. We have explored importance in rat sperm physiology by taking advantage high sensitivity for inhibitor ouabain. Using concentrations that selectively block activity, we found ouabain to reduce not only total motility, but also multiple parameters movement, including progressive straight line, curvilinear, and average path velocities, lateral...

Na,K-ATPase α4 is a testis-specific plasma membrane Na+ and K+ transporter expressed in sperm flagellum. Deletion of male mice results complete infertility, making it an attractive target for contraception. characterized by high affinity the cardiac glycoside ouabain. With goal discovering selective inhibitors function, ouabain derivatives were modified at glycone (C3) lactone (C17) domains. Ouabagenin analogue 25, carrying benzyltriazole moiety C17, picomolar inhibitor α4, with outstanding...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic Properties of the .alpha.2.beta.1 and .alpha.2.beta.2 Isoenzymes Na,K-ATPaseGustavo Blanco, Joseph C. Koster, Gladis Sanchez, Robert W. MercerCite this: Biochemistry 1995, 34, 1, 319–325Publication Date (Print):January 10, 1995Publication History Published online1 May 2002Published inissue 10 January 1995https://pubs.acs.org/doi/10.1021/bi00001a039https://doi.org/10.1021/bi00001a039research-articleACS PublicationsRequest reuse...

Abstract: The α4 polypeptide is a testis‐specific isoform of the catalytic subunit Na,K‐ATPase, which essential for sperm motility and fertility. In present study, we have investigated regulation activity relevance this event capacitation. We performed by taking advantage selective high affinity inhibitor ouabain. Our results show that ouabain‐sensitive hydrolysis ATP uptake 86 Rb, corresponding to enzymatic ion transport activities α4, respectively, increased during capacitation in...

SUMMARY Most of our knowledge on the biological role testis‐specific Na,K‐ATPase alpha 4 isoform derives from studies performed in non‐human species. Here, we studied function human after its expression transgenic mice. Using a bacterial artificial chromosome (BAC) construct containing ATP1A4 gene locus, obtained α4 transgene specifically mouse sperm testis and, flagellum. The expressed was active, and compared to wild‐type sperm, those mice displayed higher activity greater binding...

In addition to the three isoforms of catalytic subunit Na,K-ATPase originally identified (α1, α2, and α3), a fourth α polypeptide (α4) has recently been found in mammalian cells. This novel α-subunit is selectively expressed male gonadal tissues. testes, α4 functionally active comprises approximately half activity organ. At present, pattern expression within cells gonad unknown. By situ hybridization, immunocytochemistry, ouabain inhibition profile activity, we show that α4-subunit germ rat...

The ion transporter Na-K-ATPase functions as a cell signal transducer that mediates ouabain-induced activation of protein kinases, such ERK. While composed the alpha(1)-polypeptide is involved in signaling, role other alpha-isoforms (alpha(2), alpha(3), and alpha(4)) transmitting ouabain effects unknown. We have explored this using baculovirus-directed expression polypeptides insect cells ERK phosphorylation an indicator signaling. Ouabain addition to Sf-9 coexpressing alpha(1)-...

The Na-K-ATPase is part of a cell signaling complex, the signalosome, which upon activation by hormone ouabain regulates function different types. We previously showed that induces proliferation epithelial cells derived from renal cysts patients with autosomal dominant polycystic kidney disease (ADPKD cells). Here, we investigated pathways responsible for mediating effects in these cells. Incubation ADPKD ouabain, concentrations similar to those found blood, stimulated phosphorylation...

Glucose is a key substrate for supporting sperm energy production and function. Previous studies have demonstrated that glucose uptake facilitated by several isoforms of the transporters (GLUT). Here, we report also expresses Na+-dependent sodium cotransporter (SGLT). This was first suggested our observation genetic deletion testis-specific Na,K-ATPase α4, which impairs plasma membrane Na+ gradient, reduces ATP production. Immunoblot analysis revealed presence an SGLT in sperm, with specific...

Na + ,K -ATPase α4 is a unique cell plasma membrane and K transporter of spermatozoa, which essential for male fertility. Previous studies have shown that highly expressed in the sperm flagellum; however, spatial arrangement at subcellular level its relationship to functional state cells are unknown. We studied this here using stimulated emission depletion (STED) super-resolution microscopy. show that, under non-capacitated conditions, distributed trilinear pattern along midpiece as...

The Na,K-ATPase alpha4 (ATP1A4) isoform is specifically expressed in male germ cells and highly prevalent spermatozoa. Although selective inhibition of activity with ouabain has been shown to affect sperm motility, a more direct analysis the role this movement not yet demonstrated. To establish this, we engineered transgenic mice that express rat fused green fluorescent protein cells, under control mouse protamine 1 promoter. We showed Atp1a4 transgene spermatozoa it localized flagellum. In...

Renal cyst progression in autosomal dominant polycystic kidney disease (ADPKD) is highly dependent on agents circulating blood. We have previously shown, using different vitro models, that one of these the hormone ouabain. By binding to Na

The Na,K- and H,K-ATPases are plasma membrane enzymes responsible for the active exchange of extracellular K+ cytoplasmic Na+ or H+, respectively. At present, structural determinants specific function these ATPases remain poorly understood. To investigate cation selectivity ATPases, we constructed a series Na,K-ATPase mutants in which residues spanning segments α subunit were changed to corresponding common gastric H,K-ATPases. Thus, created with substitutions transmembrane domains TM1, TM4,...