title: WNK2 modulates MEK1 activity through the Rho GTPase pathway.
abstract: WNK protein kinases form a kinase subfamily expressed in multi-cellular organisms and the human genome encodes four distinct WNK genes. Human WNK2 has been recently identified as a cell growth regulator that modulates activation of the ERK1/2 protein kinase and is epigenetically silenced in gliomas. Here we provide mechanistic insight into how WNK2 affects ERK activation. We found that WNK2 depletion decreased RhoA activation and promoted GTP-loading of Rac1, leading to stimulation of the Rac1-effector PAK1, which is the kinase responsible for subsequent phosphorylation of MEK1 at serine 298, thereby increasing MEK affinity towards ERK1/2. We propose that WNK2 controls a RhoA-mediated cross-talk mechanism that regulates the efficiency with which MEK1 can activate ERK1/2 upon growth factor stimulation.
authors.affiliation: Centre of Human Genetics, National Health Institute, Lisbon, Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Moniz
authors.forename: Paulo
authors.initials: P
authors.lastname: Matos
authors.forename: Peter
authors.initials: P
authors.lastname: Jordan
mesh_terms: D002460:Cell Line; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000378:metabolism*; D010768:Phosphoserine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D054462:p21-Activated Kinases / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D010768:Phosphoserine; C523482:WNK2 protein, human; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048369:MAP Kinase Kinase 1; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein