Qi JZ, Gong JY, Zhao TJ, Zhao J (Zhao, Jie)1, Lam P, Ye J, Li JZ, Wu JW, Zhou HM, Li P. Downregulation of AMP-activated protein kinase by Cidea-mediated ubiquitination and degradation in brown adipose tissue. EMBO JOURNAL 27: 1537-1548, 2008

Abstract We previously showed that Cidea(-/-) mice are resistant to diet-induced obesity through the upregulation of energy expenditure. The AMP-activated protein kinase (AMPK), consisting of catalytic alpha subunit and regulatory subunits beta and gamma, has a pivotal function in energy homoeostasis. We show here that AMPK protein levels and enzymatic activity were significantly increased in the brown adipose tissue of Cidea(-/-) mice. We also found that Cidea is colocalized with AMPK in the endoplasmic reticulum and forms a complex with AMPK in vivo through specific interaction with the beta subunit of AMPK, but not with the alpha or gamma subunit. When co-expressed with Cidea, the stability of AMPK-beta subunit was dramatically reduced due to increased ubiquitination-mediated degradati......