title: CLASP interacts with sorting nexin 1 to link microtubules and auxin transport via PIN2 recycling in Arabidopsis thaliana.
abstract: Polarized movement of auxin generates concentration gradients within plant tissues to control cell division patterns and growth direction by modulating microtubule organization. In this study, we identify a reverse mechanism, wherein microtubules influence polar auxin transport. We show that the microtubule-associated protein CLASP interacts with the retromer component sorting nexin 1 (SNX1) to mediate an association between endosomes and microtubules. clasp-1 null mutants display aberrant SNX1 endosomes, as do wild-type plants treated with microtubule-depolymerizing drugs. Consistent with SNX1's role in trafficking of the auxin efflux carrier PIN-FORMED2 (PIN2), clasp-1 mutant plants have enhanced PIN2 degradation, and PIN2 movement to lytic vacuoles is rapidly induced by depolymerization of microtubules. clasp-1 mutants display aberrant auxin distribution and exhibit numerous auxin-related phenotypes. In addition to mechanistically linking auxin transport and microtubules, our data identify a ubiquitous endosome-microtubule association in plants.
authors.affiliation: Department of Botany, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Chris
authors.initials: C
authors.lastname: Ambrose
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ruan
authors.forename: John
authors.initials: J
authors.lastname: Gardiner
authors.forename: Laura M
authors.initials: LM
authors.lastname: Tamblyn
authors.forename: Amanda
authors.initials: A
authors.lastname: Catching
authors.forename: Viktor
authors.initials: V
authors.lastname: Kirik
authors.forename: Jan
authors.initials: J
authors.lastname: Marc
authors.forename: Robyn
authors.initials: R
authors.lastname: Overall
authors.forename: Geoffrey O
authors.initials: GO
authors.lastname: Wasteneys
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D021381:Protein Transport; D058305:Sorting Nexins / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D008869:Microtubule-Associated Proteins; D058305:Sorting Nexins; C527272:CLASP protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis