2ZV210645207565ENSG00000110931ENSMUSG00000029471Q96RR4Q8C078NM_172214NM_172215NM_172216NM_172226NM_001199676NM_145358NP_757363NP_757364NP_757365NP_757380NP_757365.1NP_001186605NP_663333Calcium/calmodulin-dependent protein kinase kinase 2 is an enzyme that in humans is encoded by the CAMKK2 gene. Calcium/calmodulin-dependent protein kinase kinase 2 is an enzyme that in humans is encoded by the CAMKK2 gene. The product of this gene belongs to the serine/threonine-specific protein kinase family, and to the Ca++/calmodulin-dependent protein kinase subfamily. This protein plays a role in the calcium/calmodulin-dependent (CaM) kinase cascade by phosphorylating the downstream kinases CaMK1 and CaMK4. CaMKK2 regulates production of the appetite stimulating hormone neuropeptide Y and functions as an AMPK kinase in the hypothalamus. It also has an important role in the development of hyperalgesia and tolerance to opioid analgesic drugs, through reduction in downstream signalling pathways and mu opioid receptor downregulation. Inhibition of CaMKK2 in mice reduces appetite and promotes weight loss. Seven transcript variants encoding six distinct isoforms have been identified for this gene. Additional splice variants have been described but their full-length nature has not been determined. The identified isoforms exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases. This article incorporates text from the United States National Library of Medicine, which is in the public domain.