title: WNK1 activates ERK5 by an MEKK2/3-dependent mechanism.
abstract: WNK1 belongs to a unique protein kinase family that lacks the catalytic lysine in its normal position. Mutations in human WNK1 and WNK4 have been implicated in causing a familial form of hypertension. Here we report that overexpression of WNK1 led to increased activity of cotransfected ERK5 in HEK293 cells. ERK5 activation was blocked by the MEK5 inhibitor U0126 and expression of a dominant negative MEK5 mutant. Expression of dominant negative mutants of MEKK2 and MEKK3 also blocked activation of ERK5 by WNK1. Moreover, both MEKK2 and MEKK3 coimmunoprecipitated with endogenous WNK1 from cell lysates. WNK1 phosphorylated both MEKK2 and -3 in vitro, and MEKK3 was activated by WNK1 in 293 cells. Finally, ERK5 activation by epidermal growth factor was attenuated by suppression of WNK1 expression using small interfering RNA. Taken together, these results place WNK1 in the ERK5 MAP kinase pathway upstream of MEKK2/3.
authors.affiliation: Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041, USA.
authors.forename: Bing-E
authors.initials: BE
authors.lastname: Xu
authors.forename: Steve
authors.initials: S
authors.lastname: Stippec
authors.forename: Lisa
authors.initials: L
authors.lastname: Lenertz
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Lee
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Youn-Kyoung
authors.initials: YK
authors.lastname: Lee
authors.forename: Melanie H
authors.initials: MH
authors.lastname: Cobb
mesh_terms: D002070:Butadienes / Q000494:pharmacology; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D007163:Immunosorbent Techniques; D047908:Intracellular Signaling Peptides and Proteins; D048671:MAP Kinase Kinase 5; D048730:MAP Kinase Kinase Kinase 2; D048748:MAP Kinase Kinase Kinase 3; D020930:MAP Kinase Kinase Kinases / Q000032:analysis / Q000502:physiology*; D015778:Minor Histocompatibility Antigens; D048054:Mitogen-Activated Protein Kinase 7; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009570:Nitriles / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D011994:Recombinant Proteins; D014162:Transfection; D000076204:WNK Lysine-Deficient Protein Kinase 1
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D015778:Minor Histocompatibility Antigens; D009570:Nitriles; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C113580:U 0126; D004815:Epidermal Growth Factor; D017346:Protein Serine-Threonine Kinases; D000076204:WNK Lysine-Deficient Protein Kinase 1; C498743:WNK1 protein, human; D048054:Mitogen-Activated Protein Kinase 7; D020928:Mitogen-Activated Protein Kinases; D048730:MAP Kinase Kinase Kinase 2; D048748:MAP Kinase Kinase Kinase 3; D020930:MAP Kinase Kinase Kinases; C482618:MAP3K2 protein, human; C482625:MAP3K3 protein, human; D048671:MAP Kinase Kinase 5; C482563:MAP2K5 protein, human; C482565:Map2k5 protein, rat; D020929:Mitogen-Activated Protein Kinase Kinases