Abstract

The Early Salt Stress-Induced 2 protein, ESI2, was identified as an interacting protein with the GTP-binding protein RAN via a His6-tag pull-down assay and by bimolecular fluorescent complementation. Fluorescent protein fusions transiently expressed in Nicotiana benthamiana were observed using confocal fluorescent microscopy. The proteins fused to independent fluorescent partners localized to separate cellular compartments, with RAN primarily localized to the nucleus and ESI2 localized primarily to the tonoplast and cytoplasm. This interaction suggests a potential mechanism for the role of ESI2 in the sequestration of RAN and possible regulation of cell division in response to stress. To further explore the role of ESI2, the protein was overexpressed in Arabidopsis however plant phenotypes were not found to differ from wild type plants.