SNF1-related protein kinase (SnRK)

SNF1-related protein kinases (SnRKs) are a family of serine/threonine protein kinases that function as cellular energy sensors and master regulators of metabolism in plants[1][2]. The SnRK family is divided into three subfamilies: SnRK1, SnRK2, and SnRK3, each with distinct structural features and biological roles[1]. SnRK1 kinases are homologous to yeast SNF1 and mammalian AMPK, functioning as heterotrimeric complexes consisting of catalytic α-subunits and regulatory β- and γ-subunits[2][3]. These kinases contain a highly conserved N-terminal catalytic kinase domain with essential residues including a conserved lysine for ATP binding and a phosphorylated threonine in the activation loop required for kinase activity[1][3]. SnRK1 serves as a key metabolic switch, regulating important enzymes including HMG-CoA reductase, sucrose phosphate synthase, nitrate reductase, and trehalose-5-phosphate synthase through direct phosphorylation, thereby controlling carbon and nitrogen metabolism, stress responses, and plant development[2]. The regulatory domain contains ubiquitin-associated (UBA) and kinase-associated 1 (KA1) domains that facilitate protein interactions and enhance catalytic activity[1]. SnRK2 kinases are central regulators of abiotic stress and ABA signaling, while SnRK3/CIPK kinases play important roles in calcium signaling pathways[1]. These kinases are activated in response to energy-depleting stress conditions and participate in a wide range of signaling pathways controlling cellular processes including plant growth, development, and environmental stress responses[1][3].

Other names

SNF1-related kinaseSNRKSNF-related serine/threonine-protein kinaseSNFRKKIAA0096FLJ20224HSNFRKSNF-1 related kinaseSucrose non-fermenting 1-related protein kinase

Protein phosphorylation, Enzyme activity regulation, Metabolic pathway control