Structural and functional analysis of essential pre-mRNA splicing factor Prp19p

Area of Science:

• Molecular Biology
• Structural Biology
• Biochemistry

Background:

• Prp19p, a U-box-containing protein, is essential for spliceosome activation.
• It is a core component of the Prp19p-associated complex (NTC) and stabilizes the complex through protein-protein interactions.

Purpose of the Study:

• To investigate the oligomeric state and structural organization of Prp19p.
• To elucidate the role of Prp19p oligomerization in NTC assembly and function.

Main Methods:

• In vitro and in vivo biochemical analyses to determine Prp19p oligomerization.
• Mapping of the oligomerization domain using protein interaction studies.
• Electron microscopy to visualize the structure of the Prp19p tetramer.

Main Results:

• Prp19p forms a stable tetramer in both in vitro and in vivo conditions.
• A central tetrameric coiled-coil domain mediates Prp19p oligomerization.
• The Prp19p tetramer presents an interaction surface for Cef1p binding.
• Electron microscopy revealed an elongated tetramer structure with globular WD40 domains and a central stalk of U-boxes and coiled-coils.

Conclusions:

• Prp19p tetramerization is a fundamental property essential for NTC stability and function.
• The structural data provide insights into Prp19p's role as a key architectural scaffold within the NTC.
• Understanding Prp19p structure-function relationships is critical for spliceosome assembly and regulation.