An internal motor kinesin is associated with the Golgi apparatus and plays a role in trichome morphogenesis in Arabidopsis.
Members of the kinesin superfamily are microtubule-based motor proteins that transport molecules/organelles along microtubules. We have identified similar internal motor kinesins, Kinesin-13A, from the cotton Gossypium hirsutum and Arabidopsis thaliana. Their motor domains share high degree of similarity with those of internal motor kinesins of animals and protists in the MCAK/Kinesin13 subfamily. However, no significant sequence similarities were detected in sequences outside the motor domain. In Arabidopsis plants carrying the T-DNA knockout kinesin-13a-1 and kinesin-13a-2 mutations at the Kinesin-13A locus, >70% leaf trichomes had four branches, whereas wild-type trichomes had three. Immunofluorescent results showed that AtKinesin-13A and GhKinesin-13A localized to entire Golgi stacks. In both wild-type and kinesin-13a mutant cells, the Golgi stacks were frequently associated with microtubules and with actin microfilaments. Aggregation/clustering of Golgi stacks was often observed in the kinesin-13a mutant trichomes and other epidermal cells. This suggested that the distribution of the Golgi apparatus in cell cortex might require microtubules and Kinesin-13A, and the organization of Golgi stacks could play a regulatory role in trichome morphogenesis. Our results also indicate that plant kinesins in the MCAK/Kinesin-13 subfamily have evolved to take on different tasks than their animal counterparts.
Lu
Ling
L
Section of Plant Biology, University of California, Davis, Davis, CA 95616, USA.
Lee
Yuh-Ru Julie
YR
Pan
Ruiqin
R
Maloof
Julin N
JN
Liu
Bo
B
D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000254:growth & development* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D007091:Image Processing, Computer-Assisted; D016547:Kinesins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D008954:Models, Biological; D009024:Morphogenesis; D016254:Mutagenesis, Insertional; D009154:Mutation; D010802:Phylogeny; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D030821:Plants, Genetically Modified / Q000648:ultrastructure; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014966:Xanthenes
D000199:Actins; D029681:Arabidopsis Proteins; D005456:Fluorescent Dyes; D011993:Recombinant Fusion Proteins; D014966:Xanthenes; D049452:Green Fluorescent Proteins; C034657:Texas red; D016547:Kinesins; D016650:Fluorescein-5-isothiocyanate