The Arabidopsis HINKEL gene encodes a kinesin-related protein involved in cytokinesis and is expressed in a cell cycle-dependent manner.
Plant cytokinesis starts in the center of the division plane, with vesicle fusion generating a new membrane compartment, the cell plate, that subsequently expands laterally by continuous fusion of newly arriving vesicles to its margin. Targeted delivery of vesicles is assisted by the dynamic reorganization of a plant-specific cytoskeletal array, the phragmoplast, from a solid cylinder into an expanding ring-shaped structure. This lateral translocation is brought about by depolymerization of microtubules in the center, giving way to the expanding cell plate, and polymerization of microtubules along the edge. Whereas several components are known to mediate cytokinetic vesicle fusion [8-10], no gene function involved in phragmoplast dynamics has been identified by mutation. Mutations in the Arabidopsis HINKEL gene cause cytokinesis defects, such as enlarged cells with incomplete cell walls and multiple nuclei. Proper targeting of the cytokinesis-specific syntaxin KNOLLE [8] and lateral expansion of the phragmoplast are not affected. However, the phragmoplast microtubules appear to persist in the center, where vesicle fusion should result in cell plate formation. Molecular analysis reveals that the HINKEL gene encodes a plant-specific kinesin-related protein with a putative N-terminal motor domain and is expressed in a cell cycle-dependent manner similar to the KNOLLE gene. Our results suggest that HINKEL plays a role in the reorganization of phragmoplast microtubules during cell plate formation.
Strompen
Georg
G
ZMBP Entwicklungsgenetik, Universität Tübingen, Auf der Morgenstelle 3, D-72076, Tübingen, Germany.
El Kasmi
Farid
F
Richter
Sandra
S
Lukowitz
Wolfgang
W
Assaad
Farhah F
FF
Jürgens
Gerd
G
Mayer
Ulrike
U
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics*; D017931:DNA Primers; D017343:Genes, Plant; D017403:In Situ Hybridization; D016547:Kinesins / Q000235:genetics*; D008565:Membrane Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D050765:Qa-SNARE Proteins; D014404:Tubulin / Q000378:metabolism
D029681:Arabidopsis Proteins; D017931:DNA Primers; C452431:HINKEL protein, Arabidopsis; C097724:KNOLLE protein, Arabidopsis; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D050765:Qa-SNARE Proteins; D014404:Tubulin; D016547:Kinesins