C. elegans dss-1 is functionally conserved and required for oogenesis and larval growth

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Dss1 (Rpn15) is a proteasome subunit linked to DNA repair, mRNA export, and exocytosis.
• Its essentiality in metazoans was unknown due to a lack of animal models.
• Fungal Dss1 orthologues are not essential for viability.

Purpose of the Study:

• To characterize the first knockout animal model for the proteasome subunit DSS-1.
• To investigate the essentiality and function of DSS-1 in metazoans.
• To explore the functional conservation of DSS-1.

Main Methods:

• Generated a dss-1 loss-of-function mutant in *Caenorhabditis elegans*.
• Utilized RNA interference (RNAi) for dss-1 knockdown.
• Created a DSS-1::GFP fusion protein for localization studies.
• Complemented a yeast *sem1* deletion mutant with *C. elegans* dss-1.

Main Results:

• *C. elegans* dss-1 is essential for oogenesis, embryogenesis, and larval growth.
• dss-1 RNAi led to embryonic lethality and larval arrest.
• DSS-1::GFP localized primarily to the nucleus.
• No significant effect on proteasome function was observed in dss-1 RNAi worms.
• *C. elegans* dss-1 rescued temperature-sensitive growth and partially rescued polyubiquitinated protein accumulation in yeast *sem1* deletion mutants.

Conclusions:

• The *C. elegans* dss-1 gene encodes an essential protein, unlike its fungal orthologues.
• DSS-1 is crucial for embryogenesis, larval growth, and oogenesis in *C. elegans*.
• The function of DSS-1 is conserved across yeast, nematode, and human homologues.