Related Experiment Video
Updated: Jul 13, 2026
14:47
Identification of MyoD Interactome Using Tandem Affinity Purification Coupled to Mass Spectrometry
Published on: May 17, 2016
Expression pattern of muscleblind-like proteins differs in differentiating myoblasts.
Kyung-Soon Lee1, Rachel M Squillace, Edith H Wang
1University of Washington, School of Medicine, Department of Pharmacology, Seattle, 1959 NE Pacific Street, Box 357280, WA 98195-7280, USA.
Biochemical and Biophysical Research Communications
|July 24, 2007
Summary
Muscleblind-like 3 (MBNL3) protein levels decrease during muscle differentiation in mouse cells. This suggests specific signaling pathways regulate MBNL3 expression, impacting myogenesis and potentially myotonic dystrophy.
Area of Science:
- Molecular Biology
- Cell Biology
- Developmental Biology
Background:
- Muscleblind-like (MBNL) proteins are key regulators of myogenesis.
- MBNL proteins are implicated in myotonic dystrophy.
- Mammalian MBNL3 acts as an inhibitor of myogenesis, contrasting with Drosophila melanogaster muscleblind's role.
Purpose of the Study:
- To investigate the expression pattern of MBNL3 in various adult mouse tissues and cell cultures.
- To understand how MBNL3 expression changes during muscle differentiation.
- To compare MBNL3 regulation with the closely related MBNL1 protein.
Main Methods:
- Analysis of MBNL3 transcript distribution in adult mouse tissues.
- Western blotting to detect MBNL3 protein levels in different cell types (C2C12 myoblasts, ts13 myofibroblasts, fibroblasts).
- Assessment of MBNL3 and MBNL1 protein levels under muscle differentiation conditions.
Main Results:
- MBNL3 transcript is notably enriched in lung, spleen, and testis, but not in cardiac or skeletal muscle.
- MBNL3 protein is present in myoblasts and myofibroblasts, with lower levels in fibroblasts.
- Upon induction of muscle differentiation, MBNL3 protein levels significantly decreased, while MBNL1 levels remained unchanged.
Conclusions:
- Myoblasts and fibroblasts exhibit distinct responses to differentiation cues.
- Signaling pathways activated during differentiation repress MBNL3 expression.
- These findings highlight a regulatory mechanism for MBNL3 during myogenesis, distinct from MBNL1 regulation.
Related Concept Videos
01:13Formation of Muscle Fibers from Myoblasts
De novo myogenesis, or the formation of muscle fibers, begins during the early embryonic stages. The skeletal muscle is formed from somites– blocks of embryonic cell layers. The somites are further divided into dermatomes, myotomes, sclerotomes, and syndetomes. Among these, the myotomes give rise to muscle fibers.
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription factors...
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription factors...
01:15Overview of Myosin Structure and Function
Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X) have been well characterized.
01:16Actin and Myosin in Muscle Contraction
Actin and myosin are contractile proteins that form the sarcomere found in skeletal muscle tissues for regulating muscle contraction. Actin, a globular contractile protein, interacts with myosin for muscle contraction. The skeletal tissue appears striped or striated under a microscope due to the repeated arrangement of contractile proteins actin and myosin along the length of myofibrils. Dark A bands and light I bands repeat along myofibrils, and the alignment of myofibrils in the cell causes...
01:13Microscopic Anatomy of Skeletal Muscles
Skeletal muscle cells, also called muscle fibers, are distinctly elongated, multi-nucleated, slender biological units. They are packed with specialized structures designed to facilitate their primary function, which is contraction.
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
01:21Satellite Stem Cells and Muscular Dystrophy
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...
01:18Role of Myosin in Cell Migration
Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...