activators
Gene Expression Regulation Gene expression can be thought of as a dimmer light switch, controlling when and where RNA molecules and proteins are made and how much of those products are made. Gene regulation is how a cell controls which genes are expressed out of the many genes in its genome. The precise regulation of gene expression allows cells to adopt and maintain their specialized roles. For example, a liver cell expresses genes related to liver function, while a muscle cell expresses genes related to muscle contraction. Gene expression can be regulated at many steps, from DNA to protein. Different genes are regulated at different points, and it’s not uncommon for important or powerful genes to be regulated at multi- ple steps. The main control point for many genes is transcription.
enhancers
Kinds of Transcription Factors Transcription factors are proteins that help turn specific genes “on” or “off” by binding to nearby DNA. They act like a control panel for gene expression. Transcription factors bind to DNA, making it easier or harder for RNA polymerase to bind to the DNA promoter. They help ensure that the right genes are expressed in the right cells of the body at the right time and in the right amounts to meet the cell's or organism's needs. Some transcription factors are generalized, serving to help RNA polymerase bind to DNA. However, large classes of transcription factors control the expression of specific, individual genes. Some transcription factors are activators , boosting a gene’s transcription. Others are repressors that decrease transcription. Far-away clusters of binding sites for transcriptional activators and repressors, called enhancers and silencers , activate or repress genes in a certain cell or body part.
repressors
Why is gene expression important for human health? Gene expression and regulation are fundamental processes in the development, maintenance, and func- tioning of organisms, which are important to their overall health. They allow cells to adapt to different conditions, including environmental changes, stress, and disease. For example, when the body is exposed to a pathogen, certain genes associated with the immune response are activated to help fight the infection. Dysregulation of gene expression can lead to various diseases. Diseases can occur when mutated genes are expressed or when important genes are turned off. For example, uncontrolled cell growth due to changes in the regulation of genes involved in cell cycle control can result in cancer. Understanding and manipulating gene expression is crucial for developing therapies to treat or prevent such diseases. n
silencers
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