ARNTL2

ARNTL2 (Aryl Hydrocarbon Receptor Nuclear Translocator-Like 2), also known as BMAL2 (Brain and Muscle ARNT-Like 2), is a protein that in humans is encoded by the ARNTL2 gene. This protein is a member of the basic helix-loop-helix (bHLH)-PAS family of transcription factors. It plays a crucial role in the regulation of circadian rhythms by forming heterodimers with other proteins such as CLOCK; these heterodimers then bind to E-box elements in the promoters of target genes, thereby regulating their expression.

Function

The ARNTL2 protein is involved in the molecular mechanism of the circadian clock, which is an internal time-keeping system that governs various physiological processes, including sleep-wake cycles, hormone release, and metabolism. Although it is less studied compared to its paralog, ARNTL (or BMAL1), ARNTL2 is believed to perform similar functions in the regulation of circadian rhythms. It can form heterodimers with CLOCK or NPAS2 proteins, which then bind to DNA and regulate the expression of genes that are important for the maintenance of circadian rhythms.

Gene and Expression

The ARNTL2 gene is located on chromosome 12 in humans. Its expression, like that of other circadian genes, is regulated in a time-dependent manner, showing fluctuations over the 24-hour day. ARNTL2 expression is not only found in the brain, where it contributes to the central circadian clock, but also in various peripheral tissues, indicating its potential role in local tissue-specific circadian rhythms.

Clinical Significance

While the full clinical significance of ARNTL2 is still being explored, alterations in its expression and function have been implicated in various disorders. Given its role in the circadian system, ARNTL2 may be involved in sleep disorders, metabolic syndrome, and other conditions where the circadian rhythm is disrupted. Further research is necessary to fully understand its contributions to health and disease.

See Also

• Circadian rhythm
• Gene expression
• Transcription factor
• BMAL1
• CLOCK (gene)
• NPAS2