Dimethyl sulfoxide affects the selection of splice sites

Area of Science:

• Molecular Biology
• Gene Expression Regulation
• Cellular Processes

Background:

• Dimethyl sulfoxide (Me2SO) is known to influence cell differentiation and apoptosis.
• The precise molecular mechanisms by which Me2SO exerts these effects are not fully understood.
• Previous studies indicate Me2SO alters gene expression, but direct molecular targets remain elusive.

Purpose of the Study:

• To identify the direct molecular processes affected by dimethyl sulfoxide (Me2SO).
• To investigate the impact of Me2SO on pre-mRNA splicing and splice site selection.
• To elucidate how Me2SO influences alternative splicing events.

Main Methods:

• In vitro splicing assays using model pre-mRNAs and HeLa cell nuclear extracts.
• Analysis of splice site selection in the presence and absence of Me2SO.
• Testing the effects of Me2SO on recombinant hnRNP A1 and SR proteins.
• Comparison of Me2SO with other polar solvents like DMF and formamide.

Main Results:

• Dimethyl sulfoxide (Me2SO) was found to alter splice site selection on model pre-mRNAs.
• A shift towards proximal splice sites was observed with Me2SO treatment.
• Me2SO activated splicing in a HeLa S100 extract and enhanced the activity of SR proteins in vitro.
• Other polar solvents showed similar effects on splice site selection, but not all activated splicing.

Conclusions:

• Dimethyl sulfoxide (Me2SO) directly impacts alternative splicing by modulating splice site selection.
• Me2SO likely enhances ionic interactions between splicing factors containing RS-domains.
• This direct effect on alternative splicing provides a partial explanation for Me2SO's varied effects on cell differentiation and apoptosis.