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A Commander-independent function of COMMD3 in endosomal trafficking
Galen T Squiers1, Chun Wan1, James Gorder1
1Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, United States.
Elife
|August 21, 2025
Summary
The Commander complex is vital for endosomal recycling. However, a subunit, COMMD3, independently regulates cargo recycling by stabilizing ARF1, revealing functions beyond the whole complex.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Endosomal recycling is crucial for intracellular trafficking, preventing cargo degradation.
- The Commander complex, a 16-subunit assembly, is key to this process.
- The precise molecular mechanism of the Commander complex is not fully understood.
Purpose of the Study:
- To genetically dissect the Commander complex.
- To elucidate the molecular mechanisms of endosomal recycling.
- To identify Commander-independent functions of its subunits.
Main Methods:
- Unbiased genetic screens
- Comparative targeted mutations
- Analysis of protein-protein interactions (COMMD3-ARF1)
Main Results:
- Identified a Commander-independent role for the COMMD3 subunit in endosomal recycling.
- COMMD3's N-terminal domain binds and stabilizes ARF1.
- Disruption of COMMD3-ARF1 interaction impairs ARF1 expression and cargo recycling.
Conclusions:
- Commander subunits can function independently of the holo-complex.
- COMMD3 regulates specific cargo recycling via ARF1 stabilization.
- This suggests other membrane trafficking complex components may also have extracomplex functions.
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