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Autocatalytic proteolysis of the transcription factor-coactivator C1 (HCF): a potential role for proteolytic

J L Vogel1, T M Kristie

  • 1Laboratory of Viral Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Proceedings of the National Academy of Sciences of the United States of America
|August 2, 2000
PubMed

Insights

Site-specific proteolysis regulates cellular processes. The C1 factor (HCF) uses autocatalytic activity for processing, potentially acting in trans.

Area of Science:

  • Molecular biology
  • Biochemistry
  • Cellular regulation

Background:

  • Site-specific proteolysis is crucial for regulating cellular functions, including gene expression and apoptosis.
  • Proteolytic processing impacts the localization and activity of regulatory factors in transcriptional regulation.

Purpose of the Study:

  • To investigate the mechanism of site-specific proteolytic processing of the C1 factor (HCF).
  • To identify the enzymatic activity responsible for cleaving HCF's amino acid reiterations.
  • To determine if the HCF protease can function in trans.

Main Methods:

  • Expression and purification of bacterially expressed domains of the C1 factor.
  • Characterization of autocatalytic activity within the C1 factor domains.
  • Coexpression of the C1 autocatalytic domain with a heterologous protein containing a target cleavage site.

Main Results:

  • An autocatalytic activity within the C1 factor was identified, responsible for cleaving unusual amino acid reiterations.
  • Proteolytic processing of HCF generates associated amino- and carboxyl-terminal polypeptides.
  • The C1 protease demonstrated potential to function in trans when coexpressed with a heterologous target protein.

Conclusions:

  • The C1 factor possesses intrinsic autocatalytic activity for site-specific proteolysis.
  • This proteolytic mechanism generates distinct HCF polypeptides that maintain association.
  • The C1 protease may play a broader role in cellular regulation by acting on other proteins in trans.

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