Protein phosphatase X interacts with c-Rel and stimulates c-Rel/nuclear factor kappaB activity.
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.
Hu
M C
MC
Department of Cell Biology, Amgen, Inc., Thousand Oaks, California 91320, USA.
Tang-Oxley
Q
Q
Qiu
W R
WR
Wang
Y P
YP
Mihindukulasuriya
K A
KA
Afshar
R
R
Tan
T H
TH
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
D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; D011994:Recombinant Proteins; D010749:Phosphoprotein Phosphatases; C080406:protein phosphatase 4