Related Experiment Video
Updated: Apr 20, 2026
09:20
Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping
Published on: March 23, 2022
2.7K
Fiber type-specific expression of LACTB leverages a function in oxidative metabolism
Kirsi-Marja Alanen1, Rabah Soliymani2, Jaakko Sarparanta3
1Biochemistry and Developmental Biology, Medicum, Faculty of Medicine, University of Helsinki, Biomedicum Helsinki 1, Haartmaninkatu 8, 00290, Helsinki, Finland.
Histochemistry and Cell Biology
|April 18, 2026
Summary
Lactate beta (LACTB) is a mitochondrial protein enriched in slow-twitch (Type I) muscle fibers. This finding suggests LACTB plays a role in oxidative metabolism and can serve as a Type I fiber marker.
Area of Science:
- Cellular biology
- Muscle physiology
- Mitochondrial function
Background:
- Skeletal muscle comprises Type I and Type II fibers with distinct metabolic properties.
- Lactate beta (LACTB), a mitochondrial protein, is linked to lipid metabolism and cancer, but its role in cellular metabolism is not fully understood.
Purpose of the Study:
- To investigate the functional role of LACTB in skeletal muscle.
- To determine if LACTB expression is specific to muscle fiber types.
Main Methods:
- Immunohistochemistry (IHC) and immunoblotting were used to analyze LACTB expression in human and rat skeletal muscle.
- Antibody specificity was confirmed using recombinant and endogenous LACTB.
- Myoblast differentiation models (C2C12, L6) were employed for validation.
Main Results:
- LACTB was found to be highly enriched in adult Type I muscle fibers.
- LACTB expression initiated during Type I myotube development in vivo.
- LACTB levels increased significantly during myoblast differentiation in vitro.
Conclusions:
- LACTB is specifically localized to the mitochondria of Type I muscle fibers.
- LACTB likely participates in oxidative metabolism, particularly lipid utilization in Type I fibers.
- LACTB serves as a novel mitochondrial marker for Type I skeletal muscle fibers.
Related Concept Videos
01:25Lipid Catabolism
1.5K
Triglycerides serve as crucial long-term energy storage molecules in microorganisms, providing a dense source of metabolic energy. Their breakdown is mediated by lipases, which hydrolyze triglycerides into glycerol and free fatty acids. Each of these components follows distinct metabolic pathways, ultimately contributing to ATP synthesis and cellular energy homeostasis.Glycerol MetabolismGlycerol, released from triglyceride hydrolysis, is phosphorylated by glycerol kinase to form...
1.5K
01:15Pyruvate Oxidation
173.1K
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
173.1K
02:36The Citric Acid Cycle
168.3K
The citric acid cycle, also known as the Krebs cycle or TCA cycle, consists of several energy-generating reactions that yield one ATP molecule, three NADH molecules, one FADH2 molecule, and two CO2 molecules.
168.3K
01:37The Citric Acid Cycle: Overview
24.7K
In aerobic organisms, the citric acid cycle is the second stage of cellular respiration wherein molecules derived from the breakdown of carbohydrates, proteins, and fats are oxidized into carbon dioxide and energy. This process is also known as the tricarboxylic acid (TCA) cycle as the first product of the cycle, citric acid, contains three carboxyl groups in its structure. Alternatively, this cycle is also referred to as the Krebs cycle, in honor of its discoverer Sir Hans Krebs.
The citric...
The citric...
24.7K
01:26Respiration Pathways
934
Cellular respiration is a fundamental metabolic process that enables organisms to generate energy from organic molecules. One of its central pathways is the tricarboxylic acid (TCA) cycle, also known as the Krebs cycle, which plays a crucial role in energy production and biosynthetic processes.Conversion of Pyruvate to Acetyl-CoAThe pyruvate generated from glycolysis undergoes oxidative decarboxylation by the pyruvate dehydrogenase complex, producing acetyl-CoA, one molecule of NADH, and one...
934
01:28The Citric Acid Cycle: Output
11.3K
The citric acid cycle is termed an amphibolic pathway as it operates both anabolically and catabolically. The cyclic reactions balance the flux of the substrates to provide an optimal concentration of NADH and ATP to the cell.
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is...
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is...
11.3K