The vacuolar protein sorting genes in insects: A comparative genome view

Area of Science:

• Cell Biology
• Genomics
• Evolutionary Biology

Background:

• Regulated vesicular trafficking is essential for eukaryotic cellular functions, involving the endomembrane system and vacuolar protein sorting (VPS) proteins.
• Approximately 50 VPS genes are known in yeast, with many conserved in mammals, forming complexes like ESCRT, retromer, and PI3K-III.
• The evolutionary conservation and diversification of VPS proteins in insects remain largely unexplored.

Purpose of the Study:

• To conduct a genomic comparative analysis of VPS proteins in yeast, humans, and 13 insect species.
• To investigate the evolutionary conservation of key VPS protein complexes (ESCRT, retromer, CORVET, HOPS, GARP, PI3K-III) across these taxa.
• To identify instances of gene expansion or loss of VPS genes within insect orders.

Main Methods:

• Genomic comparative analysis using the newly annotated Manduca sexta genome and 13 other insect genomes.
• Amino acid sequence alignments and domain/motif structure analyses.
• Comparison of VPS gene conservation and expansion patterns across yeast, human, and insect genomes.

Main Results:

• Most components of ESCRT, retromer, CORVET, HOPS, GARP, and PI3K-III are evolutionarily conserved between yeast, insects, and humans.
• In contrast to human VPS gene expansion, only four VPS genes (VPS13, VPS16, VPS33, VPS37) showed expansion in six insect orders.
• VPS2 gene expansion was observed specifically in Phthiraptera, Lepidoptera, and Coleoptera species.

Conclusions:

• This study establishes a baseline for understanding the evolution of vesicular trafficking across yeast, insect, and human genomes.
• The findings highlight conserved and divergent evolutionary trajectories of VPS genes in insects.
• Provides a foundation for future research into the specific functional roles of VPS proteins in insects.