Signal-induced degradation of I kappa B alpha requires site-specific ubiquitination.

• D C Scherer

  Department of Microbiology and Immunology, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

• J A Brockman

  Department of Microbiology and Immunology, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

• Z Chen

  Department of Microbiology and Immunology, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

• T Maniatis

  Department of Microbiology and Immunology, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

• D W Ballard

  Department of Microbiology and Immunology, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

抄録

The inhibitor protein I kappa B alpha controls the nuclear import of the transcription factor NF-kappa B. The inhibitory activity of I kappa B alpha is regulated from the cytoplasmic compartment by signal-induced proteolysis. Previous studies have shown that signal-dependent phosphorylation of serine residues 32 and 36 targets I kappa B alpha to the ubiquitin-proteasome pathway. Here we provide evidence that lysine residues 21 and 22 serve as the primary sites for signal-induced ubiquitination of I kappa B alpha. Conservative Lys-->Arg substitutions at both Lys-21 and Lys-22 produce dominant-negative mutants of I kappa B alpha in vivo. These constitutive inhibitors are appropriately phosphorylated but fail to release NF-kappa B in response to multiple inducers, including viral proteins, cytokines, and agents that mimic antigenic stimulation through the T-cell receptor. Moreover, these Lys-->Arg mutations prevent signal-dependent degradation of I kappa B alpha in vivo and ubiquitin conjugation in vitro. We conclude that site-specific ubiquitination of phosphorylated I kappa B alpha at Lys-21 and/or Lys-22 is an obligatory step in the activation of NF-kappa B.

収録刊行物

• Proceedings of the National Academy of Sciences

  Proceedings of the National Academy of Sciences 92 (24), 11259-11263, 1995-11-21

  Proceedings of the National Academy of Sciences

キーワード

• Multidisciplinary

詳細情報

• CRID: 1362544419887068672
• NII論文ID: 80008683434
• DOI: 10.1073/pnas.92.24.11259
• ISSN: 10916490
• ISSN: 00278424
• Web Site: https://pnas.org/doi/pdf/10.1073/pnas.92.24.11259
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