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The KH-type RNA-binding protein PSI is required for Drosophila viability, male fertility, and cellular mRNA

Emmanuel Labourier1, Marco Blanchette, Jennie W Feiger

  • 1Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA.

Genes & Development
|January 10, 2002
PubMed

Insights

The RNA-binding protein PSI is crucial for Drosophila development and male fertility. Its interaction with U1 snRNP is essential for regulating gene expression through pre-mRNA splicing.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Genetics

Background:

  • RNA-binding proteins and snRNP particles are key regulators of eukaryotic pre-mRNA processing and gene expression.
  • The U1 snRNP-interacting protein PSI is conserved across species.

Purpose of the Study:

  • To investigate the essential role of the PSI protein in Drosophila viability and development.
  • To determine the function of the PSI-U1 snRNP interaction domain in vivo.
  • To identify PSI target mRNAs and understand its role in pre-mRNA splicing.

Main Methods:

  • Generating and analyzing PSI null and mutant Drosophila.
  • Utilizing transgenes for rescue experiments.
  • Employing cDNA microarrays to identify target mRNAs.
  • Performing immunoprecipitation to isolate ribonucleoprotein complexes.
  • Analyzing pre-mRNA splicing patterns in mutant testes.

Main Results:

  • A null PSI mutation is lethal in Drosophila larvae, but viability is rescued by PSI transgene expression.
  • A mutant PSI lacking the U1 snRNP interaction domain rescues viability but causes male sterility due to meiosis defects.
  • cDNA microarrays identified target mRNAs with altered expression in PSI mutant males.
  • The hrp40/squid transcript exhibits altered pre-mRNA splicing in PSI mutant testes.
  • A subset of identified target transcripts associates with PSI in vivo.

Conclusions:

  • A functional interaction between PSI and the U1 snRNP is indispensable for normal Drosophila development and male fertility.
  • PSI regulates specific cellular transcripts, including hrp40/squid, through pre-mRNA splicing.
  • cDNA microarrays are effective tools for studying in vivo RNA processing defects and alternative splicing.

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