title: Heat shock protein 90 associates with monarch-1 and regulates its ability to promote degradation of NF-kappaB-inducing kinase.
abstract: Monarch-1/NLRP12 is expressed in myeloid cells and functions as a negative regulator of inflammation by inducing proteasome-mediated degradation of NF-kappaB-inducing kinase. Monarch-1 is a member of the CATERPILLER gene family, also known as the nucleotide-binding domain leucine-rich repeat gene family. This family shares strong structural homology to major immune regulators expressed in lower organisms, including plants. In plants, these disease-resistance proteins (R proteins) sense pathogenic insult and initiate a protective response to limit pathogen growth. To perform this role, many R proteins require the highly conserved chaperone molecule, heat shock protein (Hsp) 90. Using a two-dimensional gel/mass spectrometry system, we detected the association of the nucleotide-binding domain leucine-rich repeat protein Monarch-1 with heat shock proteins. Further analysis indicates that analogous to plant R proteins, Hsp90 is required for Monarch-1 activity. In human monocytes, Monarch-1 associates with Hsp90, and these complexes are sensitive to treatment with specific Hsp90 inhibitors. Disruption of these complexes results in rapid degradation of Monarch-1 via the proteasome and prevents Monarch-1-induced proteolysis of NF-kappaB-inducing kinase. This demonstrates that Hsp90 is a critical regulator of Monarch-1 anti-inflammatory activity.
authors.affiliation: Department of Microbiology and Immunology, Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Janelle C
authors.initials: JC
authors.lastname: Arthur
authors.forename: John D
authors.initials: JD
authors.lastname: Lich
authors.forename: Ramy K
authors.initials: RK
authors.lastname: Aziz
authors.forename: Malak
authors.initials: M
authors.lastname: Kotb
authors.forename: Jenny P-Y
authors.initials: JP
authors.lastname: Ting
mesh_terms: D002478:Cells, Cultured; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D009000:Monocytes / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D000097782:NF-kappaB-Inducing Kinase
chemical_list: D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D046988:Proteasome Endopeptidase Complex; D017346:Protein Serine-Threonine Kinases; D000097782:NF-kappaB-Inducing Kinase; C476731:NLRP12 protein, human