Gene expression regulation

Gene expression regulation refers to the control of the amount and timing of appearance of the functional product of a gene. The regulation of gene expression is the basis for cellular differentiation, morphogenesis and the versatility and adaptability of any organism. Gene regulation may also serve as a substrate for evolutionary change, since control of the timing, location, and amount of gene expression can have a profound effect on the functions (actions) of the gene in a cell or in a multicellular organism.

Overview

In genetics, gene expression regulation is the process by which a gene's information is converted into the structures and functions of a cell. This process is regulated by the cell's machinery, the product of which is a functional gene product. In the case of a protein-coding gene, the product is a protein that performs a function in the body.

Mechanisms

Gene expression regulation can occur at several levels in the process of gene expression. These include:

• Transcriptional regulation: This is the most common form of regulation, and it occurs at the transcriptional level. This involves the binding of transcription factors to the promoter region of a gene, which can either enhance or inhibit the transcription of the gene.

• Post-transcriptional regulation: This occurs after the RNA molecule has been transcribed, but before it is translated into a protein. This can involve the modification of the RNA molecule, such as the addition of a cap and tail, splicing, or the binding of RNA-binding proteins that can influence the stability and translation of the RNA molecule.

• Translational regulation: This occurs during the process of translation, after the RNA molecule has been transcribed. This can involve the binding of proteins to the RNA molecule that can influence the rate and efficiency of its translation into a protein.

• Post-translational regulation: This occurs after the protein has been synthesized. This can involve the modification of the protein, such as phosphorylation, which can influence the function and activity of the protein.

Role in Development and Disease

Regulation of gene expression is crucial for the development and function of all organisms. In multicellular organisms, it is the process by which cells differentiate into their various cell types. Abnormal regulation of gene expression can lead to developmental abnormalities and disease, including cancer.

See Also

• Epigenetics
• Gene silencing
• Gene activation
• Operon
• Regulatory sequence