title: Fine-scale dissection of the subdomains of polarity protein BASL in stomatal asymmetric cell division.
abstract: Cell polarity is a prerequisite for asymmetric cell divisions (ACDs) that generate cell type diversity during development of multicellular organisms. In Arabidopsis, stomatal lineage ACDs are regulated by the plant-specific protein BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL). BASL exhibits dynamic subcellular localization, accumulating initially in the nucleus, but then additionally in a highly polarized crescent at the cell cortex before division. BASL polarization requires a phosphorylation-mediated activation process, but how this is achieved remains unknown. In this study, we performed a fine-scale dissection of BASL protein subdomains and elucidated a nuclear localization sequence for nuclear import and a critical FxFP motif for cortical polarity formation, respectively. Artificially tethering BASL subdomains to the plasma membrane suggests that novel protein partner/s might exist and bind to an internal region of BASL. In addition, we suspect the existence of a protein degradation mechanism associated with the amino terminal domain of BASL that accounts for restricting its predominant expression to the stomatal lineage cells of the epidermis. Taken together, our results revealed that BASL, through its distinct subdomains, integrates multiple regulatory inputs to provide a mechanism that promotes difference during stomatal lineage ACDs.
authors.affiliation: Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Biology, 371 Serra Mall, Stanford University, Stanford, CA 94305-5020, USA HHMI, Stanford University, Stanford, CA 94305-5020, USA dong@waksman.rutgers.edu dbergmann@stanford.edu.
authors.forename: Dominique C
authors.initials: DC
authors.lastname: Bergmann
authors.affiliation: Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA Department of Biology, 371 Serra Mall, Stanford University, Stanford, CA 94305-5020, USA Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, Piscataway, NJ 08901, USA dong@waksman.rutgers.edu dbergmann@stanford.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Dong
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology*; D018613:Microscopy, Confocal; D010766:Phosphorylation; D054046:Plant Stomata / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D016133:Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; C542095:BASL protein, Arabidopsis; D018797:Cell Cycle Proteins
keywords: Arabidopsis; asymmetric cell division; cell polarity; polarity protein; stomatal development; subcellular localization.