title: Pin1At regulates PIN1 polar localization and root gravitropism.
abstract: Root gravitropism allows plants to establish root systems and its regulation depends on polar auxin transport mediated by PIN-FORMED (PIN) auxin transporters. PINOID (PID) and PROTEIN PHOSPHATASE 2A (PP2A) act antagonistically on reversible phosphorylation of PINs. This regulates polar PIN distribution and auxin transport. Here we show that a peptidyl-prolyl cis/trans isomerase Pin1At regulates root gravitropism. Downregulation of Pin1At suppresses root agravitropic phenotypes of pp2aa and 35S:PID, while overexpression of Pin1At affects root gravitropic responses and enhances the pp2aa agravitropic phenotype. Pin1At also affects auxin transport and polar localization of PIN1 in stele cells, which is mediated by PID and PP2A. Furthermore, Pin1At catalyses the conformational change of the phosphorylated Ser/Thr-Pro motifs of PIN1. Thus, Pin1At mediates the conformational dynamics of PIN1 and affects PID- and PP2A-mediated regulation of PIN1 polar localization, which correlates with the regulation of root gravitropism.
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, 10 Science Drive 4, Singapore 117543, Singapore.
authors.forename: Wanyan
authors.initials: W
authors.lastname: Xi
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, 10 Science Drive 4, Singapore 117543, Singapore.
authors.forename: Ximing
authors.initials: X
authors.lastname: Gong
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, 10 Science Drive 4, Singapore 117543, Singapore.
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, 10 Science Drive 4, Singapore 117543, Singapore.|Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, 10 Science Drive 4, Singapore 117543, Singapore.|Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117573, Singapore.
authors.forename: Yih-Cherng
authors.initials: YC
authors.lastname: Liou
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018522:Gravitropism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; D026901:Membrane Transport Proteins; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; C116363:PIN1 protein, Arabidopsis; C000606847:PIN1AT protein, Arabidopsis; C405165:PINOID protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D054648:Protein Phosphatase 2; D019696:Peptidylprolyl Isomerase