A dominant negative protein kinase C zeta subspecies blocks NF-kappa B activation

Mol Cell Biol. 1993 Aug;13(8):4770-5. doi: 10.1128/mcb.13.8.4770.

Abstract

Nuclear factor kappa B (NF-kappa B) plays a critical role in the regulation of a number of genes. NF-kappa B is a heterodimer of 50- and 65-kDa subunits sequestered in the cytoplasm complexed to inhibitory protein I kappa B. Following stimulation of cells, I kappa B dissociates from NF-kappa B, allowing its translocation to the nucleus, where it carries out the transactivation function. The precise mechanism controlling NF-kappa B activation and the involvement of members of the protein kinase C (PKC) family of isotypes have previously been investigated. It was found that phorbol myristate acetate, (PMA) which is a potent stimulant of phorbol ester-sensitive PKC isotypes, activates NF-kappa B. However, the role of PMA-sensitive PKCs in vivo is not as apparent. It has recently been demonstrated in the model system of Xenopus laevis oocytes that the PMA-insensitive PKC isotype, zeta PKC, is a required step in the activation of NF-kappa B in response to ras p21. We demonstrate here that overexpression of zeta PKC is by itself sufficient to stimulate a permanent translocation of functionally active NF-kappa B into the nucleus of NIH 3T3 fibroblasts and that transfection of a kinase-defective dominant negative mutant of zeta PKC dramatically inhibits the kappa B-dependent transactivation of a chloramphenicol acetyltransferase reporter plasmid in NIH 3T3 fibroblasts. All these results support the notion that zeta PKC plays a decisive role in NF-kappa B regulation in mammalian cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Base Sequence
  • Cell Compartmentation
  • Cloning, Molecular
  • Enhancer Elements, Genetic
  • Gene Expression Regulation
  • Genes, Dominant
  • In Vitro Techniques
  • Mice
  • Molecular Sequence Data
  • Mutation
  • NF-kappa B / metabolism*
  • Oligodeoxyribonucleotides / chemistry
  • Protein Kinase C / metabolism*
  • Transcriptional Activation
  • Transfection

Substances

  • NF-kappa B
  • Oligodeoxyribonucleotides
  • protein kinase C zeta
  • Protein Kinase C