title: Tangled localization at the cortical division site of plant cells occurs by several mechanisms.
abstract: TANGLED (TAN) is the founding member of a family of plant-specific proteins required for correct orientation of the division plane. Arabidopsis thaliana TAN is localized before prophase until the end of cytokinesis at the cortical division site (CDS), where it appears to help guide the cytokinetic apparatus towards the cortex. We show that TAN is actively recruited to the CDS by distinct mechanisms before and after preprophase band (PPB) disassembly. Colocalization with the PPB is mediated by one region of TAN, whereas another region mediates its recruitment to the CDS during cytokinesis. This second region binds directly to POK1, a kinesin that is required for TAN localization. Although this region of TAN is recruited to the CDS during cytokinesis without first colocalizing with the PPB, pharmacological evidence indicates that the PPB is nevertheless required for both early and late localization of TAN at the CDS. Finally, we show that phosphatase activity is required for maintenance of early but not late TAN localization at the CDS. We propose a new model in which TAN is actively recruited to the CDS by several mechanisms, indicating that the CDS is dynamically modified from prophase through to the completion of cytokinesis.
authors.affiliation: University of California, San Diego, Section of Cell and Developmental Biology, 9500 Gilman Dr., La Jolla, CA 92093-0116, USA. cgrasmussen@ucsd.edu
authors.forename: Carolyn G
authors.initials: CG
authors.lastname: Rasmussen
authors.forename: Brian
authors.initials: B
authors.lastname: Sun
authors.forename: Laurie G
authors.initials: LG
authors.lastname: Smith
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D016547:Kinesins / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; C525946:TANGLED protein, Arabidopsis; C511453:POK1 protein, Arabidopsis; D016547:Kinesins