MyoD, also known as myoblast determination protein 1, is a protein in animals that plays a major role in regulating muscle differentiation. MyoD, which was discovered in the laboratory of Harold M. Weintraub, belongs to a family of proteins known as myogenic regulatory factors (MRFs). These bHLH transcription factors act sequentially in myogenic differentiation. Vertebrate MRF family members include MyoD1, Myf5, myogenin, and MRF4 (Myf6). In non-vertebrate animals, a single MyoD protein is typically found.
A basic helix–loop–helix (bHLH) is a protein structural motif that characterizes one of the largest families of dimerizing transcription factors. The word "basic" does not refer to complexity but to the chemistry of the motif because transcription factors in general contain basic amino acid residues in order to facilitate DNA binding.
Myogenin, is a transcriptional activator encoded by the MYOG gene. Myogenin is a muscle-specific basic-helix-loop-helix (bHLH) transcription factor involved in the coordination of skeletal muscle development or myogenesis and repair. Myogenin is a member of the MyoD family of transcription factors, which also includes MyoD, Myf5, and MRF4.
Twist-related protein 1 (TWIST1) also known as class A basic helix–loop–helix protein 38 (bHLHa38) is a basic helix-loop-helix transcription factor that in humans is encoded by the TWIST1 gene.
Neuronal PAS domain protein 2 (NPAS2) also known as member of PAS protein 4 (MOP4) is a transcription factor protein that in humans is encoded by the NPAS2 gene. NPAS2 is paralogous to CLOCK, and both are key proteins involved in the maintenance of circadian rhythms in mammals. In the brain, NPAS2 functions as a generator and maintainer of mammalian circadian rhythms. More specifically, NPAS2 is an activator of transcription and translation of core clock and clock-controlled genes through its role in a negative feedback loop in the suprachiasmatic nucleus (SCN), the brain region responsible for the control of circadian rhythms.
Myocyte-specific enhancer factor 2C also known as MADS box transcription enhancer factor 2, polypeptide C is a protein that in humans is encoded by the MEF2C gene. MEF2C is a transcription factor in the Mef2 family.
Myocyte-specific enhancer factor 2A is a protein that in humans is encoded by the MEF2A gene. MEF2A is a transcription factor in the Mef2 family. In humans it is located on chromosome 15q26. Certain mutations in MEF2A cause an autosomal dominant form of coronary artery disease and myocardial infarction.
Transcription factor HES1 is a protein that is encoded by the Hes1 gene, and is the mammalian homolog of the hairy gene in Drosophila. HES1 is one of the seven members of the Hes gene family (HES1-7). Hes genes code nuclear proteins that suppress transcription.
Hairy/enhancer-of-split related with YRPW motif protein 1 is a protein that in humans is encoded by the HEY1 gene.
Heart- and neural crest derivatives-expressed protein 1 is a protein that in humans is encoded by the HAND1 gene.
Protein atonal homolog 1 is a protein that in humans is encoded by the ATOH1 gene.
Transcription factor AP-4 , also known as TFAP4, is a protein which in humans is encoded by the TFAP4 gene.
Twist-related protein 2 is a protein that in humans is encoded by the TWIST2 gene. The protein encoded by this gene is a basic helix-loop-helix (bHLH) transcription factor and shares similarity with another bHLH transcription factor, TWIST1. bHLH transcription factors have been implicated in cell lineage determination and differentiation. It is thought that during osteoblast development, this protein may inhibit osteoblast maturation and maintain cells in a preosteoblast phenotype.
Hairy/enhancer-of-split related with YRPW motif-like protein is a protein that in humans is encoded by the HEYL gene.
"Basic helix-loop-helix family, member e41", or BHLHE41, is a gene that encodes a basic helix-loop-helix transcription factor repressor protein in various tissues of both humans and mice. It is also known as DEC2, hDEC2, and SHARP1, and was previously known as "basic helix-loop-helix domain containing, class B, 3", or BHLHB3. BHLHE41 is known for its role in the circadian molecular mechanisms that influence sleep quantity as well as its role in immune function and the maturation of T helper type 2 cell lineages associated with humoral immunity.
Aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL) or Brain and Muscle ARNT-Like 1 (BMAL1) is a protein that in humans is encoded by the Bmal1 gene, also known as ARNTL, MOP3, and, less commonly, BHLHE5, BMAL, BMAL1C, JAP3, PASD3, and TIC.
Pho4 is a protein with a basic helix-loop-helix (bHLH) transcription factor. It is found in S. cerevisiae and other yeasts. It functions as a transcription factor to regulate phosphate responsive genes located in yeast cells. The Pho4 protein homodimer is able to do this by binding to DNA sequences containing the bHLH binding site 5'-CACGTG-3'. This sequence is found in the promoters of genes up-regulated in response to phosphate availability such as the PHO5 gene.
In molecular biology, the myogenic determination factor 5 proteins are a family of proteins found in eukaryotes. This family includes the Myf5 protein, which is responsible for directing cells to the skeletal myocyte lineage during development. Myf5 is likely to act in a similar way to the other MRF4 proteins such as MyoD which perform the same function. These are histone acetyltransferases and histone deacetylases which activate and repress genes involved in the myocyte lineage.
Proneural genes encode transcription factors of the basic helix-loop-helix (bHLH) class which are responsible for the development of neuroectodermal progenitor cells. Proneural genes have multiple functions in neural development. They integrate positional information and contribute to the specification of progenitor-cell identity. From the same ectodermal cell types, neural or epidermal cells can develop based on interactions between proneural and neurogenic genes. Neurogenic genes are so called because loss of function mutants show an increase number of developed neural precursors. On the other hand, proneural genes mutants fail to develop neural precursor cells.
(HES7) or bHLHb37 is protein coding mammalian gene found on chromosome 17 in humans. HES7 is a member of the Hairy and Enhancer of Split families of Basic helix-loop-helix proteins. The gene product is a transcription factor and is expressed cyclically in the presomitic mesoderm as part of the Notch signalling pathway. HES7 is involved in the segmentation of somites from the presomitic mesoderm in vertebrates. The HES7 gene is self-regulated by a negative feedback loop in which the gene product can bind to its own promoter. This causes the gene to be expressed in an oscillatory manner. The HES7 protein also represses expression of Lunatic Fringe (LFNG) thereby both directly and indirectly regulating the Notch signalling pathway. Mutations in HES7 can result in deformities of the spine, ribs and heart. Spondylocostal dysostosis is a common disease caused by mutations in the HES7 gene. The inheritance pattern of Spondylocostal dysostosis is autosomal recessive.
