Important scaffold function of the Janus kinase 2 uncovered by a novel mouse model harboring a Jak2 activation-loop mutation.

Janus kinases (Jak) play essential roles in cytokine and growth factor signaling. Conventional gene targeting of Jak2, creating a null allele, leads to a block in definitive erythropoiesis as a result of failing signal transduction at the homomeric erythropoietin receptor (EpoR) and at the heteromeric interferon γ receptor (IFNGR). To investigate the in vivo relevance of the activation loop of Jak2, a Jak2-YY1007/1008FF knockin mutation was introduced into the germline of mice.

PUMA-G and HM74 are receptors for nicotinic acid and mediate its anti-lipolytic effect.

Nicotinic acid (niacin), a vitamin of the B complex, has been used for almost 50 years as a lipid-lowering drug. The pharmacological effect of nicotinic acid requires doses that are much higher than those provided by a normal diet. Its primary action is to decrease lipolysis in adipose tissue by inhibiting hormone-sensitive triglyceride lipase.