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Inhibition of transcription factor activity by poliovirus

N Crawford1, A Fire, M Samuels

  • 1Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.

Cell
|December 1, 1981
PubMed

Insights

Poliovirus infection inhibits host-cell RNA synthesis by depleting a key transcription factor. This study found that infected cell extracts lack a necessary component for RNA polymerase II, impacting DNA transcription.

Area of Science:

  • Molecular Biology
  • Virology
  • Biochemistry

Background:

  • Poliovirus infection disrupts host cell processes, including RNA synthesis.
  • Understanding the molecular mechanisms of viral interference with host transcription is crucial.

Purpose of the Study:

  • To investigate the poliovirus-induced inhibition of host-cell RNA synthesis.
  • To identify the specific molecular defect responsible for reduced RNA polymerase II activity.

Main Methods:

  • Preparation of transcription extracts from mock-infected and poliovirus-infected HeLa cells.
  • Assessing the specific transcription of DNA templates by RNA polymerase II and III.
  • Supplementation assays with transcription factors (S100) and purified polymerase II.
  • Fractionation of S100 on a phosphocellulose column.

Main Results:

  • Poliovirus-infected cell extracts showed significantly reduced specific DNA transcription by RNA polymerase II.
  • Accurate transcription by RNA polymerase III was only slightly affected.
  • Supplementation with S100 restored RNA polymerase II transcription, while purified polymerase II had no effect.
  • The essential factor eluted between 0.35 M and 1 M KCl during S100 fractionation.

Conclusions:

  • Poliovirus infection leads to a deficiency in a host cell factor required for specific RNA polymerase II transcription.
  • This deficiency, rather than a direct inhibitory molecule, appears to be the cause of impaired host-cell RNA synthesis.

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