A novel method to investigate the effects of gene mutations at the cellular level using a dual expression lentiviral...

Area of Science:

• Molecular Biology
• Gene Regulation
• Cellular Biology

Background:

• Studying gene mutations conventionally involves transfecting mammalian cells, but endogenous gene expression interference often yields unsatisfactory results.
• A superior method is needed to accurately investigate the cellular effects of gene mutations.

Purpose of the Study:

• To develop and validate a novel dual expression lentiviral vector system for studying gene mutations.
• To investigate the impact of transcription factor IIA gamma (TFIIAγ) gene mutations on cellular transcription and protein-DNA interactions.

Main Methods:

• Constructed a dual expression lentiviral vector system combining shRNA and exogenous gene expression.
• Generated vectors expressing TFIIAγ shRNA and HA-TFIIAγ or its mutants.
• Utilized transient and stable cell lines for analysis.
• Employed chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) to assess protein-DNA interactions.

Main Results:

• The dual expression system successfully silenced endogenous TFIIAγ while preserving exogenous HA-TFIIAγ expression.
• Mutations in a conserved domain of TFIIAγ (AA62-69) impaired promoter activity, endogenous gene expression, and TFIIAγ binding to the AdML core promoter.
• The TFIIAγ N63A mutant reduced the recruitment of TFIIAγ, polymerase II (Pol II), TATA box-binding protein (TBP), and TBP-associated factor 1 (TAF1) to the IGF2 promoter, inhibiting its transcription.

Conclusions:

• The developed dual expression lentiviral vector offers a robust method for investigating gene mutations at the cellular level.
• This system overcomes limitations of traditional methods by eliminating endogenous gene interference.
• TFIIAγ mutations significantly affect gene transcription and protein-DNA binding, providing insights into gene regulation mechanisms.