The AAA + ATPase valosin-containing protein (VCP)/p97/Cdc48 interaction network in Leishmania

Area of Science:

• Molecular Biology
• Parasitology
• Proteomics

Background:

• Valosin-containing protein (VCP)/p97/Cdc48 is an AAA+ ATPase vital for ubiquitin-dependent cellular pathways, including protein quality control.
• VCP function is modulated by cofactors, dictating pathway selectivity and substrate processing.
• Understanding VCP networks in parasitic organisms is crucial for identifying potential therapeutic targets.

Purpose of the Study:

• To identify the Leishmania infantum VCP (LiVCP) interactome.
• To predict molecular interactions between LiVCP and its major cofactors.
• To build the first VCP protein interaction network in parasitic protozoa.

Main Methods:

• Co-immunoprecipitation and mass spectrometry were employed to identify LiVCP interactors.
• In silico analyses, including 3D homology modeling and protein-protein docking, were used for interaction prediction.
• Network proteomics, Gene Ontology analysis, digitonin fractionation, and immunofluorescence studies characterized LiVCP complexes and cofactor localization.

Main Results:

• A largely conserved VCP protein network was identified in Leishmania, including known and novel interaction partners.
• Network proteomics confirmed LiVCP-cofactor interactions and revealed cofactor-specific partners and diverse VCP complexes.
• In silico models indicated conserved cofactor binding to LiVCP, similar to eukaryotic orthologs, with distinct binding sites.

Conclusions:

• The study successfully constructed the first VCP protein interaction network in parasitic protozoa.
• Identified interactions provide insights into VCP complex diversity and cofactor roles in Leishmania.
• The findings lay the groundwork for understanding VCP-mediated processes in parasitic diseases.