Cotton plasma membrane intrinsic protein 2s (PIP2s) selectively interact to regulate their water channel activities and are required for fibre development
Cotton plasma membrane intrinsic protein 2s (PIP2s) selectively interact to regulate their water channel activities and are required for fibre development
复制标题
棉花质膜内在蛋白 2s (PIP2s) 选择性地相互作用以调节其水通道活性，并且是纤维发育所必需的
DOI：
10.1111/nph.12309
复制
发表时间：
2013-08-01
期刊：
影响因子：
9.4
通讯作者：
Li, Xue-Bao
中科院分区：
文献类型：
--
作者：
Li, Deng-Di;Ruan, Xiang-Mei;Li, Xue-Bao
水通道蛋白被认为与水分运输有关，并在棉花(Gossypium Hirsutom)纤维伸长中发挥重要作用。在水通道蛋白中，质膜内源蛋白(PIPs)是一个质膜特异性亚家族，又分为PIP1和PIP2两大类。GhPIP2；3与GhPIP2；4和GhPIP2；6相互作用，而GhPIP2；6不与GhPIP2相互作用；4.共表达GhPIP2；3/2；4或GhPIP2；3/2；6对卵母细胞有正协同作用，提高卵母细胞的透性系数。GhBCP2(一种蓝色铜结合蛋白)通过它们的相互作用抑制GhPIP2；6的水通道活性。GhPIP2基因在酵母中的过表达诱导宿主细胞的纵向生长。相反，通过RNA干扰抑制GhPIP2基因在棉花中的表达明显阻碍了纤维的伸长。它们选择性地形成杂低聚物，以调节它们的活性，以满足纤维快速伸长的要求。
Aquaporins are thought to be associated with water transport and play important roles in cotton (Gossypium hirsutum) fibre elongation. Among aquaporins, plasma membrane intrinsic proteins (PIPs) constitute a plasma-membrane-specific subfamily and are further subdivided into PIP1 and PIP2 groups.In this study, four fibre-preferential GhPIP2 genes were functionally characterized. The selective interactions among GhPIP2s and their interaction proteins were studied in detail to elucidate the molecular mechanism of cotton fibre development.GhPIP2;3 interacted with GhPIP2;4 and GhPIP2;6, but GhPIP2;6 did not interact with GhPIP2;4. Coexpression of GhPIP2;3/2;4 or GhPIP2;3/2; 6 resulted in a positive cooperative effect which increased the permeability coefficient of oocytes, while GhPIP2;4/2;6 did not. GhBCP2 (a blue copper-binding protein) inhibited GhPIP2;6 water channel activity through their interaction. Overexpression of GhPIP2 genes in yeast induced longitudinal growth of the host cells. By contrast, knockdown of expression of GhPIP2 genes in cotton by RNA interference markedly hindered fibre elongation.In conclusion, GhPIP2 proteins are the primary aquaporin isoforms in fibres. They selectively form hetero-oligomers in order to regulate their activities to meet the requirements for rapid fibre elongation.