title: Phosphorylation switch modulates the interdigitated pattern of PIN1 localization and cell expansion in Arabidopsis leaf epidermis.
abstract: Within a multicellular tissue cells may coordinately form a singular or multiple polar axes, but it is unclear whether a common mechanism governs different types of polar axis formation. The phosphorylation status of PIN proteins, which is directly affected by the PINOID (PID) protein kinase and the PP2A protein phosphatase, is known to regulate the apical-basal polarity of PIN localization in bipolar cells of roots and shoot apices. Here, we provide evidence that the phosphorylation status-mediated PIN polarity switch is widely used to modulate cellular processes in Arabidopsis including multipolar pavement cells (PC) with interdigitated lobes and indentations. The degree of PC interdigitation was greatly reduced either when the FYPP1 gene, which encodes a PP2A called phytochrome-associated serine/threonine protein phosphatase, was knocked out or when the PID gene was overexpressed (35S::PID). These genetic modifications caused PIN1 localization to switch from lobe to indentation regions. The PP2A and PID mediated switching of PIN1 localization is strikingly similar to their regulation of the apical-basal polarity switch of PIN proteins in other cells. Our findings suggest a common mechanism for the regulation of PIN1 polarity formation, a fundamental cellular process that is crucial for pattern formation both at the tissue/organ and cellular levels.
authors.affiliation: National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Hongjiang
authors.initials: H
authors.lastname: Li
authors.forename: Deshu
authors.initials: D
authors.lastname: Lin
authors.forename: Pankaj
authors.initials: P
authors.lastname: Dhonukshe
authors.forename: Shingo
authors.initials: S
authors.lastname: Nagawa
authors.forename: Dandan
authors.initials: D
authors.lastname: Chen
authors.forename: Jiří
authors.initials: J
authors.lastname: Friml
authors.forename: Ben
authors.initials: B
authors.lastname: Scheres
authors.forename: Hongwei
authors.initials: H
authors.lastname: Guo
authors.forename: Zhenbiao
authors.initials: Z
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D048430:Cell Shape / Q000235:genetics*; D055786:Gene Knockout Techniques; D007210:Indoleacetic Acids / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D019441:Plant Epidermis / Q000166:cytology* / Q000502:physiology; D018515:Plant Leaves / Q000166:cytology* / Q000502:physiology; 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; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; C405165:PINOID protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; C472136:FyPP1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2