HK3 — Arabidopsis thaliana

Summary

AT1G27320 (HK3, also known as AHK3 or ROCK3) on chromosome 1 encodes a transmembrane histidine kinase cytokinin receptor with histidine phosphotransfer kinase activity, classified as EC 2.7.13.3. The protein contains CHASE, histidine kinase, and receiver domains. HK3 is associated with cytokinin perception, breakdown, and transport, as well as osmosensor activity. It has been linked to numerous traits including leaf senescence, salt and freezing tolerance, plant height, biomass formation, seed yield, floral organ size, root meristem development, and water use efficiency. The gene is associated with vasculogenesis, embryonic root morphogenesis, regulation of chlorophyll catabolism, and cellular responses to sucrose. Localization evidence places the product at the plasma membrane, ER membrane, plastid, and nucleus. Studies of related genes in other species link the family to adventitious root development and stomatal immunity.