Inhibition of NF-kappa B by S-nitrosylation.

Published

Journal Article

It is not clear if redox regulation of transcription is the consequence of direct redox-related modifications of transcription factors, or if it occurs at some other redox-sensitive step. One obstacle has been the inability to demonstrate redox-related modifications of transcription factors in vivo. The redox-sensitive transcriptional activator NF-kappaB (p50-p65) is a case in point. Its activity in vitro can be inhibited by S-nitrosylation of a critical thiol in the DNA-interacting p50 subunit, but modulation of NF-kappaB activity by nitric oxide synthase (NOS) has been attributed to other mechanisms. Herein we show that cellular NF-kappaB activity is in fact regulated by S-nitrosylation. We observed that both S-nitrosocysteine and cytokine-activated NOS2 inhibited NF-kappaB in human respiratory cells or murine macrophages. This inhibition was reversed by addition of the denitrosylating agent dithiothreitol to cellular extracts, whereas NO bioactivity did not affect the TNFalpha-induced degradation of IkappaBalpha or the nuclear translocation of p65. Recapitulation of these conditions in vitro resulted in S-nitrosylation of recombinant p50, thereby inhibiting its binding to DNA, and this effect was reversed by dithiothreitol. Further, an increase in S-nitrosylated p50 was detected in cells, and the level was modulated by TNFalpha. Taken together, these data suggest that S-nitrosylation of p50 is a physiological mechanism of NF-kappaB regulation.

Full Text

Duke Authors

Cited Authors

  • Marshall, HE; Stamler, JS

Published Date

  • February 13, 2001

Published In

Volume / Issue

  • 40 / 6

Start / End Page

  • 1688 - 1693

PubMed ID

  • 11327828

Pubmed Central ID

  • 11327828

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi002239y

Language

  • eng

Conference Location

  • United States