title: TYPE-ONE PROTEIN PHOSPHATASE4 regulates pavement cell interdigitation by modulating PIN-FORMED1 polarity and trafficking in Arabidopsis.
abstract: In plants, cell morphogenesis is dependent on intercellular auxin accumulation. The polar subcellular localization of the PIN-FORMED (PIN) protein is crucial for this process. Previous studies have shown that the protein kinase PINOID (PID) and protein phosphatase6-type phosphatase holoenzyme regulate the phosphorylation status of PIN1 in root tips and shoot apices. Here, we show that a type-one protein phosphatase, TOPP4, is essential for the formation of interdigitated pavement cell (PC) pattern in Arabidopsis (Arabidopsis thaliana) leaf. The dominant-negative mutant topp4-1 showed severely inhibited interdigitated PC growth. Expression of topp4-1 gene in wild-type plants recapitulated the PC defects in the mutant. Genetic analyses suggested that TOPP4 and PIN1 likely function in the same pathway to regulate PC morphogenesis. Furthermore, colocalization, in vitro and in vivo protein interaction studies, and dephosphorylation assays revealed that TOPP4 mediated PIN1 polar localization and endocytic trafficking in PCs by acting antagonistically with PID to modulate the phosphorylation status of PIN1. In addition, TOPP4 affects the cytoskeleton pattern through the Rho of Plant GTPase-dependent auxin-signaling pathway. Therefore, we conclude that TOPP4-regulated PIN1 polar targeting through direct dephosphorylation is crucial for PC morphogenesis in the Arabidopsis leaf.
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Xiaola
authors.initials: X
authors.lastname: Guo
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Qin
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Jia
authors.initials: J
authors.lastname: Yan
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Yali
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Bingyao
authors.initials: B
authors.lastname: Huang
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Liping
authors.initials: L
authors.lastname: Guan
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Dongtao
authors.initials: D
authors.lastname: Ren
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.).
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China (X.G., Q.Q., J.Y., Y.N., B.H., L.G., J.L., S.H.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China (Y.L., D.R.) housw@lzu.edu.cn.
authors.forename: Suiwen
authors.initials: S
authors.lastname: Hou
mesh_terms: D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D016764:Cell Polarity / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D004843:Epistasis, Genetic / Q000187:drug effects; D005816:Genetic Complementation Test; D007210:Indoleacetic Acids / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009024:Morphogenesis / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D063245:Plant Development / Q000187:drug effects; D018515:Plant Leaves / Q000166:cytology* / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D054645:Protein Phosphatase 1 / Q000378:metabolism
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C000604153:type-one protein phosphatase TOPP4, Arabidopsis