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Updated: May 19, 2026
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Analysis of the Mitochondrial Density and Longitudinal Distribution in Rat Live-Skeletal Muscle Fibers by Confocal Microscopy
Published on: December 1, 2023
Serum Response Factor (SRF)-cofilin-actin signaling axis modulates mitochondrial dynamics
Henning Beck1, Kevin Flynn, Katrin S Lindenberg
1Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, 72076 Tübingen, Germany.
Summary
Actin dynamics, specifically filamentous actin (F-actin), are crucial for maintaining healthy neuronal mitochondria size and number. Disruptions in this actin-cofilin-serum response factor (SRF) pathway contribute to neurodegenerative disease hallmarks.
Area of Science:
- Neuroscience
- Cell Biology
- Mitochondrial Dynamics
Background:
- Aberrant mitochondrial function, morphology, and transport characterize neurodegenerative diseases.
- Neuronal mitochondrial transport has been primarily attributed to microtubules, with actin involved in short-range movements.
Purpose of the Study:
- To investigate the impact of actin dynamics on neuronal mitochondrial size and localization.
- To explore the role of the serum response factor (SRF) pathway in regulating mitochondrial dynamics.
Main Methods:
- Analysis of F-actin and G-actin levels and their effects on mitochondrial morphology and abundance in neurons.
- Investigation of SRF-deficient neurons and the effects of constitutively active SRF-VP16.
- Examination of the connection between SRF, cofilin, and actin dynamics in modulating mitochondrial function.
Main Results:
- F-actin increased mitochondrial size and number, while G-actin promoted fragmentation.
- SRF deficiency led to mitochondrial fragmentation, impaired motility, and disrupted ATP metabolism.
- Constitutively active SRF-VP16 formed mitochondrial networks and rescued huntingtin (HTT)-impaired dynamics.
Conclusions:
- The SRF-cofilin-actin signaling axis is a key regulator of neuronal mitochondrial dynamics.
- Actin's role extends beyond anchoring to actively modulating mitochondrial morphology and function.
- This pathway represents a potential therapeutic target for neurodegenerative diseases.
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