Related Experiment Video
Updated: Jun 27, 2025
06:37
Analyzing Satellite Cell Function During Skeletal Muscle Regeneration by Cardiotoxin Injury and Injection of Self-delivering siRNA In Vivo
Published on: September 18, 2019
14.8K
Cox7a1 controls skeletal muscle physiology and heart regeneration through complex IV dimerization
Carolina García-Poyatos1, Prateek Arora2, Enrique Calvo3
1Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain; Centro de Investigación Biomédica en red en Fragilidad y Envejecimiento saludable (CIBERFES), Madrid, Spain.
Developmental Cell
|May 3, 2024
Summary
The study reveals that Cox7a1 is crucial for mitochondrial supercomplex assembly and muscle maturation. Its absence in zebrafish impairs Complex IV formation and alters cardiac regeneration, highlighting its role in the oxidative phosphorylation system.
Area of Science:
- Mitochondrial biology
- Cellular respiration
- Biochemistry
Background:
- The oxidative phosphorylation (OXPHOS) system's supercomplex assembly is vital for cellular energy production but not fully understood.
- Respiratory complexes form super-assembled quaternary structures, influencing energetic efficiency.
- Cox7a2l (Scaf1) is known to facilitate super-assembly of Complex III and Complex IV (CIII-CIV).
Purpose of the Study:
- To investigate the role of Cox7a1 in mitochondrial supercomplex assembly and muscle physiology.
- To understand the distinct functions of Cox7a family members in OXPHOS.
Main Methods:
- Utilized zebrafish models lacking Cox7a1 (cox7a1-/-).
- Assessed mitochondrial respiratory complex assembly, specifically Complex IV (CIV) dimer formation.
- Analyzed metabolic profiles and muscle performance.
- Examined cardiac regenerative responses.
Main Results:
- Zebrafish lacking Cox7a1 showed reduced CIV dimer formation.
- Metabolic alterations and a non-pathological decline in muscle performance were observed.
- cox7a1-/- hearts exhibited a pro-regenerative metabolic profile, affecting cardiac regeneration.
- Distinct phenotypes between cox7a1-/- and cox7a2l-/- highlight varied roles in supercomplex formation.
Conclusions:
- Cox7a1 plays a significant role in mitochondrial supercomplex assembly and muscle maturation within the OXPHOS system.
- Impaired supercomplex formation due to Cox7a1 deficiency has diverse metabolic and physiological consequences.
- Cox7a1's function is distinct from Cox7a2l, emphasizing the specialized roles of Cox7a family members.
Related Concept Videos
01:20Excitation-Contraction Coupling in Skeletal Muscles
8.2K
Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action...
When an action...
8.2K
01:13Structure of Cardiac Muscles
10.4K
Cardiac muscle, or myocardium, is a specialized type of muscle found exclusively in the heart. Its unique structural and functional characteristics enable the heart to perform its vital role of pumping blood throughout the body continuously and rhythmically. The cardiac muscle cells, or cardiomyocytes, possess an endomysium and perimysium but do not have an epimysium.
Compared to skeletal muscles, cardiac muscle cells are small and mostly have a single nucleus. Additionally, they are usually...
Compared to skeletal muscles, cardiac muscle cells are small and mostly have a single nucleus. Additionally, they are usually...
10.4K
01:21Satellite Stem Cells and Muscular Dystrophy
2.0K
Satellite stem cells or myosatellite cells are quiescent stem cells that Alexander Mauro first identified in 1961. These cells are located between the sarcolemma, the plasma membrane of muscle fibers, and the basal lamina, the connective tissue sheath covering it. These mononucleated cells are activated in response to muscle injury, can transform into myoblasts, and may form or repair muscle fibers. Myosatellite cells can provide additional myonuclei for muscle regeneration or return to a...
2.0K
01:24Generation of Action Potential in Skeletal Muscles
4.4K
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
4.4K
01:43Electron Transport Chain: Complex III and IV
7.4K
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
7.4K
01:26Cross-bridge Cycle
117.4K
As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
117.4K