Identification of an H₂O₂ permeable PIP aquaporin in barley and a serine residue promoting H₂O₂ transport

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• 作者：Jiye Rhee ; Tomoaki Horie ; Shizuka Sasano ; Yoshiki Nakahara and Maki Katsuhara
• 刊名：Physiologia Plantarum
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：159
• 期：1
• 页码：120-128
• 全文大小：2263K
• ISSN：1399-3054

文摘

A barley (Hordeum vulgare) plasma membrane type aquaporin, HvPIP2;5, was identified as an H₂O₂ permeable aquaporin among 21 barley and rice PIPs examined in the heterologous expression system using Saccharomyces cerevisiae. Four TIPs were also detected as H₂O₂-transporting aquaporins among 15 barley and rice TIPs. Influx of H₂O₂ into yeast cells expressing HvPIP2;5 was determined with a florescent-dye-based assay. Indirect immunofluorescence indicated that the expression of HvPIP2;5 protein was ubiquitous in root tissues, and was also weakly observed in leaf epidermal cells and cells in the vascular bundle. Point mutated variants of HvPIP2;5 were generated by the site-directed mutagenesis. Growth assays of yeast cells expressing these mutated HvPIP2;5 proteins suggested that Ser-126 in HvPIP2;5 has a large impact on H₂O₂ transport with a minor influence on the HvPIP2;5-mediated water transport.