Physiological roles ofpost-translational modifications of water channel aquaporin-5 in the salivary glands.

在唾液腺细胞中研究了水通道水通道蛋白-5(AQP5)的两种翻译后修饰：磷酸化和短链泛素化。我们报道，AQP5通过cAMP信号通路在质膜上被快速、瞬时地磷酸化，这种磷酸化可能不参与AQP5在细胞内的转运。钙离子诱导的AQP5短链泛素化的作用由于技术上的困难、泛素化的少量和AQP5的结构性内化而未能明确。然而，我们发现AQP5的磷酸化和泛素化相互影响彼此的修饰。

Two types of post-translational modifications, phosphorylation and short-chain ubiquitination, of water channel aquaporin-5 (AQP5) were investigated in the salivary gland cells. We reported that AQP5 is rapidly and transiently phosphorylated at the plasma membrane through the cAMP signaling pathway and this phosphorylation may not be involved in the intracellular AQP5 trafficking. A role of Ca2+-induced short-chain ubiquitination of AQP5 could not be cleared because of technical difficulties, small amount of its ubiquitination and the constitutive internalization of AQP5. However, we found that phosphorylation and ubiquitination of AQP5 affect each other’s modification.