Ishibashi Kenichi, Tanaka Yasuko, Morishita Yoshiyuki
Division of Pathophysiology, Meiji Pharmaceutical University, Tokyo, Japan.
Division of Nephrology, Saitama Medical Center, Jichi Medical University, Ohmiya, Saitama-City, Saitama, Japan.
Adv Exp Med Biol. 2023;1398:81-98. doi: 10.1007/978-981-19-7415-1_6.
Aquaporins (AQPs) are present not only in three domains of life, bacteria, eukaryotes, and archaea, but also in viruses. With the accumulating arrays of AQP superfamily, the evolutional relationship has attracted much attention with multiple publications on "the genome-wide identification and phylogenetic analysis" of AQP superfamily. A pair of NPA boxes forming a pore is highly conserved throughout the evolution and renders key residues for the classification of AQP superfamily into four groups: AQP1-like, AQP3-like, AQP8-like, and AQP11-like. The complexity of AQP family has mostly been achieved in nematodes and subsequent evolution has been directed toward increasing the number of AQPs through whole-genome duplications (WGDs) to extend the tissue specific expression and regulation. The discovery of the intracellular AQP (iAQP: AQP8-like and AQP11-like) and substrate transports by the plasma membrane AQP (pAQP: AQP1-like and AQP3-like) have accelerated the AQP research much more toward the transport of substrates with complex profiles. This evolutionary overview based on a simple classification of AQPs into four subfamilies will provide putative structural, functional, and localization information and insights into the role of AQP as well as clues to understand the complex diversity of AQP superfamily.
水通道蛋白（AQPs）不仅存在于生命的三个域——细菌、真核生物和古细菌中，还存在于病毒中。随着水通道蛋白超家族成员数量的不断增加，其进化关系受到了广泛关注，有多篇关于水通道蛋白超家族“全基因组鉴定和系统发育分析”的论文发表。一对形成孔道的NPA盒在整个进化过程中高度保守，并且为将水通道蛋白超家族分为四组提供了关键残基：水通道蛋白1样、水通道蛋白3样、水通道蛋白8样和水通道蛋白11样。水通道蛋白家族的复杂性主要在线虫中得以体现，随后的进化朝着通过全基因组复制（WGDs）增加水通道蛋白数量的方向发展，以扩展组织特异性表达和调控。细胞内水通道蛋白（iAQP：水通道蛋白8样和水通道蛋白11样）以及质膜水通道蛋白（pAQP：水通道蛋白1样和水通道蛋白3样）对底物的转运的发现，进一步加速了水通道蛋白在具有复杂特征底物转运方面的研究。基于将水通道蛋白简单分为四个亚家族的这种进化概述，将提供假定的结构、功能和定位信息，以及对水通道蛋白作用的见解，还有理解水通道蛋白超家族复杂多样性的线索。
