Potential calcium sensor. Interacts with TON1A and TON1B (PubMed:18757558). Interacts with SAC3A and SAC3B (PubMed:19843313). Interacts with UCH1 and UCH2 (PubMed:22951400). By wounding and infection by the bacterial pathogens X.campestris and P.syringae. Although assigned as a calmodulin family member by Ref.6, it only contains EF-hand domains.