Expression and localization of Arabidopsis synaptotagmins
Boris Voigt1,*, Molly Craxton2, Bazbek Davletov2, Patrick J. Hussey3, Diedrik Menzel1, František Baluška1
1 Institute of Molecular and Cellular Biology, University of Bonn, Bonn, Germany
2 MRC Laboratory of Molecular Biology, Cambridge, UK
3 Integrative Cell Biology Laboratory, University of Durham, Durham, UK
Synaptotagmins are known Ca2+ dependent triggers of exocytosis and endocytosis in animals with nervous system. Sequence analysis of various animal and plant genomes revealed the presence of synaptotagmin genes in all animals and land plants, but there is no evidence of synaptotagmin genes in unicellular organisms or those with simple forms of multicellularity. Synaptotagmins have a common structure, a N-terminal transmembrane sequence is followed by a linker and two distinct C2 domains, C2A and C2B. These two domains are known Ca2+ binding domains, but there is nothing more known about the function of the proteins in plants. To get more information about the 6 members of the Arabidopsis synaptotagmin gene family, we are investigating expression patterns by promotor-GUS fusions and cellular localizations by GFP-fusions as well as antibody labelings. Preliminary data suggest that the members of the synaptotagmin gene family are differently expressed, but show similar cellular localization.