Endocytosis restricts Arabidopsis KNOLLE syntaxin to the cell division plane during late cytokinesis.
Cytokinesis represents the final stage of eukaryotic cell division during which the cytoplasm becomes partitioned between daughter cells. The process differs to some extent between animal and plant cells, but proteins of the syntaxin family mediate membrane fusion in the plane of cell division in diverse organisms. How syntaxin localization is kept in check remains elusive. Here, we report that localization of the Arabidopsis KNOLLE syntaxin in the plane of cell division is maintained by sterol-dependent endocytosis involving a clathrin- and DYNAMIN-RELATED PROTEIN1A-dependent mechanism. On genetic or pharmacological interference with endocytosis, KNOLLE mis-localizes to lateral plasma membranes after cell-plate fusion. Fluorescence-loss-in-photo-bleaching and fluorescence-recovery-after-photo-bleaching experiments reveal lateral diffusion of GFP-KNOLLE from the plane of division to lateral membranes. In an endocytosis-defective sterol biosynthesis mutant displaying lateral KNOLLE diffusion, KNOLLE secretory trafficking remains unaffected. Thus, restriction of lateral diffusion by endocytosis may serve to maintain specificity of syntaxin localization during late cytokinesis.
Boutté
Yohann
Y
Department of Plant Physiology, Umeå Plant Science Centre (UPSC), Umeå University, Umeå, Sweden.
Frescatada-Rosa
Márcia
M
Men
Shuzhen
S
Chow
Cheung-Ming
CM
Ebine
Kazuo
K
Gustavsson
Anna
A
Johansson
Lenore
L
Ueda
Takashi
T
Moore
Ian
I
Jürgens
Gerd
G
Grebe
Markus
M
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D048749:Cytokinesis / Q000235:genetics / Q000502:physiology*; D004705:Endocytosis / Q000502:physiology*; D018519:Meristem / Q000737:chemistry / Q000378:metabolism; D010840:Phytosterols / Q000032:analysis / Q000378:metabolism; D030821:Plants, Genetically Modified; D050765:Qa-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013997:Time Factors; D014018:Tissue Distribution
D029681:Arabidopsis Proteins; C097724:KNOLLE protein, Arabidopsis; D010840:Phytosterols; D050765:Qa-SNARE Proteins