The Early Salt-Stress Induced 2 protein, ESI2, from wheat (Triticum aestivum) was identified as an interacting protein with the GTP-binding protein RAN1. Localization of both ESI2, and RAN1, has been performed using fluorescent protein fusions, transiently expressed in Nicotiana belthamiana, and observed using confocal fluorescent microscopy. The proteins fused to independent fluorescent partners localized to separate cellular compartments, with RAN1 primarily localized to the nucleus. However, the interaction of the two proteins detected by bimolecular fluorescent complementation, was found to be localized to the tonoplast. This interaction suggests a potential mechanism for the role of ESI2 in the sequestration of RAN1 and the regulation of cell division in response to stress. Two additional proteins, expressed in wheat during stress response and shown previously, by Y2H assays to bind with ESI2, where also localized. To further explore the effects of RAN1 on cell division in plants, a homozygous mutant for the Arabidopsis Ran1 was identified and a change in root growth shortly after germination was noted
