Functional characterization of the KNOLLE-interacting t-SNARE AtSNAP33 andits role in plant cytokinesis

Citation
M. Heese et al., Functional characterization of the KNOLLE-interacting t-SNARE AtSNAP33 andits role in plant cytokinesis, J CELL BIOL, 155(2), 2001, pp. 239-249
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
155
Issue
2
Year of publication
2001
Pages
239 - 249
Database
ISI
SICI code
0021-9525(20011015)155:2<239:FCOTKT>2.0.ZU;2-M
Abstract
Cytokinesis requires membrane fusion during cleavage-furrow ingression in a nimals and cell plate formation in plants. In Arabidopsis, the Sec1 homolog ue KEULE (KEU) and the cytokinesis-specific syntaxin KNOLLE (KN) cooperate to promote vesicle fusion in the cell division plane. Here, we characterize AtSNAP33, an Arabidopsis homologue of the t-SNARE SNAP25, that was identif ied as a KN interactor in a yeast two-hybrid screen. AtSNAP33 is a ubiquito usly expressed membrane-associated protein that accumulated at the plasma m embrane and during cell division colocalized with KN at the forming cell pl ate. A T-DNA insertion in the AtSNAP33 gene caused loss of AtSNAP33 functio n, resulting in a lethal dwarf phenotype. atsnap33 plantlets gradually deve loped large necrotic lesions on cotyledons and rosette leaves, resembling p athogen-induced cellular responses, and eventually died before flowering. i n addition, mutant seedlings displayed cytokinetic defects, and atsnap33 in combination with the cytokinesis mutant keu was embryo lethal. Analysis of the Arabidopsis genome revealed two further SNAP25-like proteins that also interacted with KN in the yeast two-hybrid assay. Our results suggest that AtSNAP33, the first SNAP25 homologue characterized in plants, is involved in diverse membrane fusion processes, including cell plate formation, and t hat AtSNAP33 function in cytokinesis may be replaced partially by other SNA P25 homologues.