Related Experiment Video
Updated: Jul 8, 2026
11:02
Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos
Published on: April 29, 2011
Intramolecular regulation of MyoD activation domain conformation and function
J Huang1, H Weintraub, L Kedes
1Institute for Genetic Medicine and Department of Biochemistry and Molecular Biology, University of Southern California School of Medicine, Los Angeles, California 90033, USA.
Molecular and Cellular Biology
|August 26, 1998
Summary
Mutations in the MyoD basic helix-loop-helix (bHLH) protein
Area of Science:
- Molecular Biology
- Protein Conformation
- Gene Regulation
Background:
- MyoD proteins are crucial for muscle cell development.
- The basic region of MyoD binds DNA, while the N-terminus activates transcription.
- A specific mutation (Ala-114) disrupts myogenic activation.
Purpose of the Study:
- To investigate the structural and functional consequences of the Ala-114 mutation in MyoD.
- To elucidate the mechanism by which this mutation abolishes myogenic activation.
Main Methods:
- Conformational analysis of the MyoD basic region mutant.
- Assessing the impact of altered basic region conformation on the activation domain.
Main Results:
- The Ala-114 mutation alters the basic region's conformation.
- This local conformational change induces a global effect on the activation domain's structure.
- Defective conformation, not just DNA binding, underlies the mutation's detrimental effects.
Conclusions:
- MyoD activation is dependent on correct basic region conformation for unmasking the activation domain.
- This coupled conformational mechanism ensures myogenic specificity among bHLH proteins.
- Understanding these conformational dynamics is key to deciphering myogenic determination.
Related Concept Videos
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
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.
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
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...
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...