Involved in resistance to abiotic stress. Heterodimers (PubMed:29272523). Interacts with CYSTM6, CYSTM7 and WIH1/CYSTM13 (PubMed:29272523). Mostly expressed in stems, siliques, leaves and flowers and, to a lower extent, in roots. Induced by heat. Belongs to the CYSTM1 family.