Water Adaptation Strategy in Anuran Amphibians: Molecular Diversity of Aquaporin
Water Adaptation Strategy in Anuran Amphibians: Molecular Diversity of Aquaporin
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DOI：
10.1210/en.2009-0841
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发表时间：
2010-01-01
期刊：
影响因子：
4.8
通讯作者：
Tanaka, Shigeyasu
中科院分区：
文献类型：
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作者：
Ogushi, Yuji;Akabane, Gen;Tanaka, Shigeyasu
除了水生物种外，大多数成年无尾两栖动物通过腹侧骨盆皮肤吸收水分，并在膀胱中从尿液中重新吸收。许多陆生和树栖物种使用腹面皮肤后部或骨盆区域的区域，该区域专门用于从浅水源或潮湿基质中快速补液。在陆地活动的时间可以通过从膀胱重吸收稀释的尿液而延长。水通道蛋白（AQP）是一种水通道蛋白，在这些水吸收/重吸收过程中起着重要作用，这些过程受抗利尿激素的调节。对各种无尾两栖类水通道蛋白的研究表明，无尾两栖类特有的水平衡主要由两种类型的水通道蛋白介导，即腹侧骨盆皮肤和膀胱型水通道蛋白。膀胱型AQP进一步表达在陆生和树栖物种的骨盆皮肤中，以及骨盆皮肤型AQP。相比之下，水栖爪蟾的骨盆皮肤型AQP（AQP-x3）已经失去了有效生产蛋白质的能力。AQP-x3编码区C末端额外的33个核苷酸组成的尾巴似乎参与AQP-x3基因表达的转录后调节，通过减弱蛋白质的表达。膀胱型水通道蛋白在骨盆皮肤中的正转录调节和骨盆皮肤型水通道蛋白的负转录后调节提供了水调节机制的灵活性，这可能有助于无尾两栖类对各种水环境的进化适应。（内分泌学151：165-173，2010）
Most adult anuran amphibians except for the aquatic species absorb water across the ventral pelvic skin and reabsorb it from urine in the urinary bladder. Many terrestrial and arboreal species use a region in the posterior or pelvic region of the ventral skin that is specialized for rapid rehydration from shallow water sources or moist substrates. Periods of terrestrial activity can be prolonged by reabsorption of dilute urine from the urinary bladder. Aquaporin (AQP), a water channel protein, plays a fundamental role in these water absorption/reabsorption processes, which are regulated by antidiuretic hormone. Characterization of AQPs from various anurans revealed that the unique water homeostasis is basically mediated by two types of anuran-specific AQPs, i.e. ventral pelvic skin and urinary bladder type, respectively. The bladder-type AQP is further expressed in the pelvic skin of terrestrial and arboreal species, together with the pelvic skin-type AQP. In contrast, the pelvic skin-type AQP (AQP-x3) of the aquatic Xenopus has lost the ability of efficient protein production. The extra C-terminal tail in AQP-x3 consisting of 33 nucleotides within the coding region appears to participate in the posttranscriptional regulation of AQP-x3 gene expression by attenuating protein expression. The positive transcriptional regulation of bladder-type AQP in the pelvic skin and negative posttranscriptional regulation of pelvic skin-type AQP provide flexibility in the water regulation mechanisms, which might have contributed to the evolutionary adaptation of anurans to a wide variety of water environments. (Endocrinology 151: 165-173, 2010)