title: Protein phosphatase X interacts with c-Rel and stimulates c-Rel/nuclear factor kappaB activity.
abstract: Nuclear factor kappaB (NF-kappaB) and the Rel family of proteins are pleiotropic transcription factors that play central roles in the immune and inflammatory responses, as well as apoptosis. Here, we identified a serine/threonine protein phosphatase X (PPX; also called protein phosphatase 4 (PP4)) that specifically associated with c-Rel, NF-kappaB p50, and RelA. The amino acid sequences of human and mouse PPX are 100% identical, and the PPX gene was mapped to human chromosome 16 p11.2. Overexpression of PPX, but not catalytically inactive PPX mutants, stimulated the DNA-binding activity of c-Rel and activated NF-kappaB-mediated transcription. These results suggest that PPX is a novel activator of c-Rel/NF-kappaB.
authors.affiliation: Department of Cell Biology, Amgen, Inc., Thousand Oaks, California 91320, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Hu
authors.forename: Q
authors.initials: Q
authors.lastname: Tang-Oxley
authors.forename: W R
authors.initials: WR
authors.lastname: Qiu
authors.forename: Y P
authors.initials: YP
authors.lastname: Wang
authors.forename: K A
authors.initials: KA
authors.lastname: Mihindukulasuriya
authors.forename: R
authors.initials: R
authors.lastname: Afshar
authors.forename: T H
authors.initials: TH
authors.lastname: Tan
mesh_terms: D000818:Animals; D002460:Cell Line; D002874:Chromosome Mapping; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020569:Proto-Oncogene Proteins c-rel; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; D011994:Recombinant Proteins; D010749:Phosphoprotein Phosphatases; C080406:protein phosphatase 4