Identification of cellular pathways affected by Sortin2, a synthetic compound that affects protein targeting to the vacuole in Saccharomyces cerevisiae.
BACKGROUND
Sortin2 is a low mass compound that interferes with vacuolar delivery of proteins in plants and yeast. The Sortin2 phenotype was tested in Arabidopsis thaliana and found to be reversible upon drug removal, demonstrating the ability of chemical genomics to induce reversible phenotypes that would be difficult to achieve using conventional genetics 1. However, standard genetic methods can be used to identify drug target pathways in a high-throughput manner.


RESULTS
In this study, we analyzed structure-function relationships of Sortin2 using structural analogues. The results show the key roles of sulphite substitution and a benzoic acid group. A Sortin 2 hypersensitivity screen for the induced secretion of a vacuolar cargo protein was done utilizing a yeast haploid deletion library. Using bioinformatics approaches, we highlighted functional information about the cellular pathways affected by drug treatment which included protein sorting and other endomembrane system-related processes.


CONCLUSIONS
Chemical, genomic and genetics approaches were used to understand the mode of action of Sortin2, a bioactive chemical that affects the delivery of a vacuolar protein. Critical features of Sortin2 structure necessary for bioactivity suggest a binding pocket that may recognize two ends of Sortin2. The genome-wide screen shows that Sortin2 treatment in yeast affects primarily components within the endomembrane system. This approach allowed us to assign putative functions in protein sorting for fifteen genes of previously unknown function.
Norambuena
Lorena
L
Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile.|Center for Plant Cell Biology and Department of Botany and Plant Sciences at University of California. 2109 Batchelor Hall, University of California Riverside, CA 92521 USA.
Zouhar
Jan
J
Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, E-28049 Madrid, Spain.|Center for Plant Cell Biology and Department of Botany and Plant Sciences at University of California. 2109 Batchelor Hall, University of California Riverside, CA 92521 USA.
Hicks
Glenn R
GR
Center for Plant Cell Biology and Department of Botany and Plant Sciences at University of California. 2109 Batchelor Hall, University of California Riverside, CA 92521 USA.
Raikhel
Natasha V
NV
Center for Plant Cell Biology and Department of Botany and Plant Sciences at University of California. 2109 Batchelor Hall, University of California Riverside, CA 92521 USA.