Repression of cell-cell fusion by components of the C. elegans vacuolar ATPase complex

Area of Science:

• Cell biology
• Developmental biology
• Molecular genetics

Background:

• Cell-cell fusion is crucial for fertilization, development, stem cell reprogramming, and potentially cancer.
• Mechanisms controlling partner specificity in cell fusion remain largely unknown.

Purpose of the Study:

• To identify genes that regulate cell fusion specificity in C. elegans.
• To elucidate the molecular mechanisms underlying the repression of inappropriate cell fusion.

Main Methods:

• Genetic screening in C. elegans to identify mutants with altered cell fusion.
• Analysis of gene function and protein localization using microscopy.
• Biochemical characterization of gene products, including V-ATPase subunits.

Main Results:

• The fus-1 gene is essential for repressing epidermal cell fusion in C. elegans.
• Loss of fus-1 function results in hyperfusion of epidermal cells, requiring the EFF-1 fusion protein.
• FUS-1 localizes to the apical plasma membrane of fusion-competent cells.
• fus-1 encodes a subunit of the vacuolar H(+)-ATPase (V-ATPase); loss of other V-ATPase subunits also causes hyperfusion.

Conclusions:

• The V-ATPase complex, through FUS-1, plays a critical role in repressing cell-cell fusion.
• These findings suggest V-ATPase activity can be targeted to manipulate cell fusion processes.