Plant Physiol, June 2002, Vol. 129, pp. 530-539

NPSN11 Is a Cell Plate-Associated SNARE Protein That Interacts with the Syntaxin KNOLLE¹

Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1312 (H.Z., A.A.S., N.V.R.); Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1544 (S.Y.B.); Plant Biology Laboratory Salk Institute Genomic Analysis Laboratory (SIGnAL), The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037; and Department of Botany and Plant Sciences and The Center for Plant Cell Biology, 2109 Batchelor Hall, University of California, Riverside, California 92521 (N.V.R.)

SNAREs are important components of the vesicle trafficking machinery in eukaryotic cells. In plants, SNAREs have been found to play a variety of roles in the development and physiology of the whole organism. Here, we describe the identification and characterization of a novel plant-specific SNARE, NPSN11, a member of a closely related small gene family in Arabidopsis. NSPN11 is highly expressed in actively dividing cells. In a subcellular fractionation experiment, NSPN11 cofractionates with the cytokinesis-specific syntaxin, KNOLLE, which is required for the formation of the cell plate. By immunofluorescence microscopy, NSPN11 was localized to the cell plate in dividing cells. Consistent with the localization studies, NSPN11 was found to interact with KNOLLE. Our results suggest that NPSN11 is another component of the membrane trafficking and fusion machinery involved in cell plate formation.