Search results
Results from the WOW.Com Content Network
Enhancers function as a "turn on" switch in gene expression and will activate the promoter region of a particular gene while silencers act as the "turn off" switch. Though these two regulatory elements work against each other, both sequence types affect the promoter region in very similar ways. [ 4 ]
An enhancer localized in a DNA region distant from the promoter of a gene can have a very large effect on gene expression, with some genes undergoing up to 100-fold increased expression due to an activated enhancer. [32] Enhancers are regions of the genome that are major gene-regulatory elements. Enhancers control cell-type-specific gene ...
This region is known as the enhancer region. Studies have suggested that thyroid hormone (T3) controls Sox2 expression via the enhancer region. The expression of TRα1 (thyroid hormone receptor) is increased in proliferating and migrating neural stem cells.
Enhancers are bound by transcription activator proteins and transcriptional regulation is typically controlled by more than one activator. Enhanceosomes are formed in special cases when these activators cooperatively bind together along the enhancer sequence to create a distinct three-dimensional structure.
H3K4me1 is a chromatin signature of enhancers, H3K4me2 is highest toward the 5′ end of transcribing genes and H3K4me3 is highly enriched at promoters and in poised genes. H3K27me3 , H4K20me1 and H3K4me1 silence transcription in embryonic fibroblasts, macrophages, and human embryonic stem cells (ESCs).
T-cell development and activation is controlled by complementary placement of proximal and distal lck promoters. The generated environment of a Lck-PROX mice when approached with proximal promoter demonstrates maximal lck protein and normal thymic development, while distal promoters lead to deficient lck protein and unnormal thymic levels.
EZH2, as a part of PRC2, catalyzes trimethylation of H3K27 (), which is a histone modification that has been characterized as part of the histone code.[16] [20] [21] [22] The histone code is the theory that chemical modifications, such as methylation, acetylation, and ubiquitination, of histone proteins play distinctive roles in epigenetic regulation of gene transcription.
MyoD, also known as myoblast determination protein 1, [5] 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, [6] belongs to a family of proteins known as myogenic regulatory factors (MRFs). [7]