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ARMC1 partitions between distinct complexes and assembles MIRO with MTFR to control mitochondrial distribution.
Michael J McKenna1, Felix Kraus1, João P L Coelho1,2
1Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA.
Science Advances
|April 9, 2025
Summary
ARMC1 protein partitioning controls mitochondrial distribution by forming complexes that regulate movement and stability. This balance, involving MIRO-MTFR and DNAJC11, is crucial for cellular energy homeostasis.
Area of Science:
- Cell Biology
- Mitochondrial Dynamics
- Molecular Mechanisms
Background:
- Optimal mitochondrial distribution is essential for cellular energy and metabolite supply.
- The precise mechanisms cells use to balance mitochondrial dynamics for homeostasis are not fully understood.
Purpose of the Study:
- To investigate the role of ARMC1 in regulating mitochondrial distribution.
- To elucidate the molecular complexes and interactions governing ARMC1's function in mitochondrial trafficking.
Main Methods:
- Analysis of ARMC1 partitioning between mitochondrial protein complexes.
- Investigating the roles of MIRO, MTFR, and DNAJC11 in ARMC1-mediated mitochondrial regulation.
- Studying the effects of disrupting specific protein complex assemblies on mitochondrial distribution.
Main Results:
- ARMC1 partitioning between MIRO-MTFR and DNAJC11 complexes determines mitochondrial distribution.
- MIRO-MTFR complexes, dependent on ARMC1, inhibit retrograde mitochondrial movement.
- DNAJC11 facilitates ARMC1 release from mitochondria, balancing its localization.
- Disrupting MIRO-MTFR assembly does not rescue ARMC1 deletion phenotypes, while disrupting ARMC1-DNAJC11 interaction causes mitochondrial defects.
Conclusions:
- ARMC1 is a key determinant of mitochondrial distribution through its interactions within distinct protein complexes.
- The balance of ARMC1's mito-cytoplasmic shuttling, regulated by DNAJC11, fine-tunes steady-state mitochondrial distributions.
- Understanding ARMC1's role provides insights into maintaining cellular energy homeostasis through mitochondrial regulation.
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