Role of cysteine residues of p65/NF-kappaB on the inhibition by the sesquiterpene lactone parthenolide and N-ethyl maleimide, and on its transactivating potential

Life Sci. 2004 Jul 2;75(7):841-56. doi: 10.1016/j.lfs.2004.01.024.


Sesquiterpene lactones (SLs) are potent anti-inflammatory substances. It was previously shown that the anti-inflammatory effect could be partly explained by the inhibition of the transcription factor NF-kappaB. Whether they inhibit the DNA binding of NF-kappaB, the activation of the IkappaB-kinase, or both is still a matter of debate. The data supporting these hypotheses were obtained using different cell systems. In this contribution we analyzed the mechanism of the sesquiterpene lactone-mediated inhibition using different cell systems, and showed that in all the cell lines analyzed, SLs inhibited both NF-kappaB binding and the IkappaB-kinase, but that the former played a more preponderant role in the inhibition. These results again confirm the importance of cysteine 38 in the inhibition and regulation of NF-kappaB's function. Moreover, we compared the selectivity of the SL parthenolide with that of N-ethyl maleimide (NEM). We showed that NEM directly alkylated p65 as well as p50 of NF-kappaB, whereas SLs possess a selectivity towards p65. Finally, we studied the transactivating properties of various p65 mutants, to analyze the effect of exchanged cysteine residues in the DNA binding domain of NF-kappaB/p65 on its function and demonstrated that the transactivating potential of the mutants did not correlate with their DNA binding strenght.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Calcium-Binding Proteins*
  • Cysteine*
  • DNA-Binding Proteins / antagonists & inhibitors*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Ethylmaleimide / pharmacology*
  • HeLa Cells
  • Humans
  • I-kappa B Kinase
  • Jurkat Cells
  • Macrophages
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mutation
  • NF-kappa B* / antagonists & inhibitors
  • NF-kappa B* / genetics
  • NF-kappa B* / metabolism
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Protein Serine-Threonine Kinases / antagonists & inhibitors
  • Sesquiterpenes / pharmacology*
  • Synaptotagmin I
  • Synaptotagmins
  • Transcription Factor RelA
  • Transcriptional Activation / drug effects*
  • Transfection


  • Anti-Inflammatory Agents, Non-Steroidal
  • Calcium-Binding Proteins
  • DNA-Binding Proteins
  • Membrane Glycoproteins
  • NF-kappa B
  • Nerve Tissue Proteins
  • Sesquiterpenes
  • Synaptotagmin I
  • Transcription Factor RelA
  • Synaptotagmins
  • parthenolide
  • Protein Serine-Threonine Kinases
  • CHUK protein, human
  • Chuk protein, mouse
  • I-kappa B Kinase
  • IKBKB protein, human
  • IKBKE protein, human
  • Ikbkb protein, mouse
  • Ikbke protein, mouse
  • Cysteine
  • Ethylmaleimide