The ubiquitin-associated domain of AMPK-related protein kinases allows LKB1-induced phosphorylation and activation.
The AMPK (AMP-activated protein kinase)-related protein kinase subfamily of the human kinome comprises 12 members closely related to the catalytic alpha1/alpha2 subunits of AMPK. The precise role of the AMPK-related kinases and their in vivo substrates is rather unclear at present, but some are involved in regulating cell polarity, whereas others appear to control cellular differentiation. Of the 12 human AMPK-related protein kinase family members, 11 can be activated following phosphorylation of their T-loop threonine residue by the LKB1 complex. Nine of these AMPK-related kinases activated by LKB1 contain an UBA (ubiquitin-associated) domain immediately C-terminal to the kinase catalytic domain. In this issue of the Biochemical Journal, Jaleel et al. show that the presence of an UBA domain in AMP-related kinases allows LKB1-induced phosphorylation and activation. The findings have implications for understanding the molecular mechanisms of activation of this fascinating family of protein kinases. Also, mutations in the UBA domains of the AMP-related kinase genes might be present in families with Peutz-Jehgers syndrome and in other cancer patients.
Hormone and Metabolic Research Unit, Christian de Duve Institute of Cellular Pathology and Université catholique de Louvain, Avenue Hippocrate 75, B-1200 Brussels, Belgium. rider@horm.ucl.ac.be
Mark H
MH
Rider
D000091162:AMP-Activated Protein Kinase Kinases; D055372:AMP-Activated Protein Kinases; D000818:Animals; D001665:Binding Sites; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D006801:Humans; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000378:metabolism*
D009097:Multienzyme Complexes; D025801:Ubiquitin; C526181:PRKAA2 protein, human; D017346:Protein Serine-Threonine Kinases; C109790:STK11 protein, human; D000091162:AMP-Activated Protein Kinase Kinases; D055372:AMP-Activated Protein Kinases; C526180:PRKAA1 protein, human