Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Via E. Orabona 4, 70125 Bari, Italy.
Int J Mol Sci. 2022 Jan 19;23(3):1048. doi: 10.3390/ijms23031048.
H/K ATPase Type 2 is an heteromeric membrane protein involved in cation transmembrane transport and consists of two subunits: a specific α subunit (ATP12A) and a non-specific β subunit. The aim of this study was to demonstrate the presence and establish the localization of ATP12A in spermatozoa from , and . Immunoblotting revealed, in all three species, a major band (100 kDa) corresponding to the expected molecular mass. The ATP12A immunolocalization pattern showed, consistently in the three species, a strong signal at the acrosome. These results, described here for the first time in spermatozoa, are consistent with those observed for the β subunit of Na/K ATPase, suggesting that the latter may assemble with the α subunit to produce a functional ATP12A dimer in sperm cells. The above scenario appeared to be nicely supported by 3D comparative modeling and interaction energy calculations. The expression of ATP12A during different stages of bovine sperm maturation progressively increased, moving from epididymis to deferent ducts. Based on overall results, we hypothesize that ATP12A may play a role in acrosome reactions. Further studies will be required in order to address the functional role of this target protein in sperm physiology.
H/K ATPase Type 2 是一种参与阳离子跨膜转运的异源膜蛋白，由两个亚基组成：一个特异性的α亚基（ATP12A）和一个非特异性的β亚基。本研究旨在证明 ATP12A 在精子中的存在并确定其定位。免疫印迹在这三个物种中均显示出一个主要的条带（100 kDa），与预期的分子质量相对应。ATP12A 的免疫定位模式在这三个物种中均显示出在顶体处有强烈的信号。这些结果在精子中首次被描述，与 Na/K ATPase 的β亚基观察到的结果一致，表明后者可能与α亚基组装，在精子细胞中产生功能性的 ATP12A 二聚体。3D 比较建模和相互作用能计算很好地支持了上述设想。ATP12A 在牛精子成熟的不同阶段的表达逐渐增加，从附睾到输精管。基于总体结果，我们假设 ATP12A 可能在顶体反应中发挥作用。需要进一步的研究来确定该靶蛋白在精子生理学中的功能作用。
