Functional Differentiation among the Arabidopsis Phosphatidylinositol 4-Phosphate 5-Kinase Genes PIP5K1, PIP5K2 and PIP5K3
Functional Differentiation among the Arabidopsis Phosphatidylinositol 4-Phosphate 5-Kinase Genes PIP5K1, PIP5K2 and PIP5K3
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拟南芥磷脂酰肌醇 4-磷酸 5-激酶基因 PIP5K1、PIP5K2 和 PIP5K3 的功能分化
DOI：
10.1093/pcp/pcac025
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发表时间：
2022
影响因子：
4.9
通讯作者：
Takashi Aoyama
中科院分区：
文献类型：
--
作者：
Machiko Watari;Mariko Kato;Romain Blanc-Mathieu;Tomohiko Tsuge;Hiroyuki Ogata;Takashi Aoyama
磷脂酰肌醇4-磷酸5-激酶（PIP 5 K）通过其产物磷脂酰肌醇（4，5）-二磷酸的信号传导功能参与调节各种细胞过程。高等植物编码大量的PIP 5 Ks，在它们的分子系统发育树中形成不同的分支。虽然PIP 5 K基因的生物学功能已经在拟南芥中得到了深入的分析，但这些功能在旁系同源进化枝中的差异仍不清楚。我们对编码PIP 5 K1、PIP 5 K2和PIP 5 K3的拟南芥基因进行了比较功能分析，以阐明它们的保守和/或分化功能。对其单个和多个突变体的遗传分析表明，PIP 5 K1和PIP 5 K3具有不重叠的功能，前者在植物总生长中，后者在根毛伸长中，而PIP 5 K2在这两种现象中具有冗余功能。这种功能冗余的模式可以用它们的启动子活性的重叠模式来解释。在转化拯救实验中，PIP 5 K3启动子指导的PIP 5 K1-YFP完全拯救了PIP 5 k3的短根毛表型。然而，在PIP 5 K1启动子的指导下，PIP 5 K3-YFP只能部分替代PIP 5 K1-YFP来挽救pip 5 k1和pip 5 k2的严重矮化。被子植物PIP 5 Ks的系统发育分析表明，PIP 5 K3的直系同源物有一个更快的速度在其氨基酸序列的多样化相比，PIP 5 K1/2的直系同源物后，他们通过一个真双子叶植物特异性的重复事件。这些结果表明，PIP 5 K3专门促进根毛的伸长，并失去了PIP 5 K1和PIP 5 K2保留的一些蛋白编码功能，而PIP 5 K1仅在其启动子指导的表达模式中与PIP 5 K2分化。
Phosphatidylinositol 4-phosphate 5-kinase (PIP5K) is involved in regulating various cellular processes through the signaling function of its product, phosphatidylinositol (4,5)-bisphosphate. Higher plants encode a large number of PIP5Ks forming distinct clades in their molecular phylogenetic tree. Although biological functions of PIP5K genes have been analyzed intensively inArabidopsis thaliana, it remains unclear how those functions differ across clades of paralogs. We performed comparative functional analysis of theArabidopsisgenes encoding PIP5K1, PIP5K2 and PIP5K3, of which the first two and the last belong to closely related but distinct clades, to clarify their conserved and/or differentiated functions. Genetic analysis with their single and multiple mutants revealed thatPIP5K1andPIP5K3have non-overlapping functions, with the former in total plant growth and the latter in root hair elongation, whereasPIP5K2redundantly functions in both phenomena. This pattern of functional redundancy is explainable in terms of the overlapping pattern of their promoter activities. In transformation rescue experiments,PIP5K3promoter-directed PIP5K1-YFP completely rescued the short-root-hair phenotype ofpip5k3. However, PIP5K3-YFP could substitute for PIP5K1-YFP only partially in rescuing the severe dwarfism ofpip5k1pip5k2when directed by thePIP5K1promoter. Phylogenetic analysis of angiosperm PIP5Ks revealed that PIP5K3 orthologs have a faster rate of diversification in their amino-acid sequences compared with PIP5K1/2 orthologs after they arose through a eudicot-specific duplication event. These findings suggest thatPIP5K3specialized to promote root hair elongation and lost some of the protein-encoded functions retained byPIP5K1andPIP5K2, whereasPIP5K1differentiated fromPIP5K2only in its promoter-directed expression pattern.