Na⁺/K⁺-ATPase is responsible for maintaining electrochemical gradients of Na⁺ and K⁺, which is essential for a variety of cellular functions including neuronal activity. The α-subunit of the Na⁺/K⁺-ATPase is composed of four different polypeptides (α1–α4) encoded by different genes. Na,K-ATPase α4, encoded by the ATP1A4 gene, is expressed in testis and in male germ cells of humans, rats and mice. The α4 polypeptide has an important role in sperm motility, and is essential for male fertility.

Here we present the RT-PCR cloning and characterization of the porcine ATP1A4 cDNA coding for Na⁺/K⁺-ATPase polypeptide α4. The Na⁺/K⁺-ATPase polypeptide α4, consisting of 1030 amino acids, displays a high homology with its human counterpart (86%). Phylogenetic analysis demonstrated that porcine Na⁺/K⁺-ATPase polypeptide α4 is closely related to other mammalian counterparts. In addition, the genomic structure of the porcine ATP1A4 gene was determined, and the intron-exon organization was found to be similar to that of the human ATP1A4 gene. The promoter sequence for the porcine ATP1A4 gene was also identified. Investigation of the genetic variation in the porcine ATP1A4 gene revealed a missense A/G SNP in exon 18. This A/G polymorphism results in a substitution of a methionine to a glycine residue (M888G). A very high overall DNA methylation rate of the ATP1A4 gene, 70–80%, was observed in both brain and liver. Expression analysis demonstrated that the porcine ATP1A4 gene is predominantly expressed in testis.

The sequence of the porcine ATP1A4 cDNA encoding the Na⁺/K⁺-ATPase α4 protein has been submitted to GenBank under the accession number GenBank Accession No. MG587082.

Na ⁺ / K ⁺ -ATPase负责维持Na ⁺和K ^+的电化学梯度，这对于包括神经元活性在内的多种细胞功能至关重要。Na ⁺ / K ⁺ -ATPase的α亚基由不同基因编码的四种不同多肽（α1-α4）组成。由ATP1A4基因编码的Na，K- ATPaseα4在睾丸以及人类，大鼠和小鼠的雄性生殖细胞中表达。α4多肽在精子运动中起重要作用，并且对男性生育至关重要。

在这里，我们介绍了RT-PCR克隆和编码Na + / K + -ATPase多肽α4的猪ATP1A4 cDNA的表征。由1030个氨基酸组成的Na + / K + -ATP酶多肽α4显示出与人类对应物（86％）的高度同源性。系统发育分析表明，猪Na + / K + -ATPase多肽α4与其他哺乳动物相似。另外，确定了猪ATP1A4基因的基因组结构，发现内含子-外显子的组织与人ATP1A4基因的组织相似。还鉴定了猪ATP1A4基因的启动子序列。猪ATP1A4的遗传变异研究该基因揭示了外显子18中的错义A / G SNP。这种A / G多态性导致蛋氨酸被甘氨酸残基（M888G）取代。在大脑和肝脏中，ATP1A4基因的总体DNA甲基化率都很高，为70–80％。表达分析表明，猪ATP1A4基因主要在睾丸中表达。

编码Na + / K + -ATP酶α4蛋白的猪ATP1A4 cDNA的序列已以登录号GenBank登录号MG587082提交给GenBank。