NPAS2

NPAS2 (Neuronal PAS Domain Protein 2) is a protein that in humans is encoded by the NPAS2 gene. It is a member of the basic helix-loop-helix-PER-ARNT-SIM (bHLH-PAS) family of transcription factors.

Function

The NPAS2 protein is a transcription factor that is highly expressed in the brain, particularly in the forebrain, a region involved in higher cognitive functions. It is thought to play a key role in maintaining the circadian rhythm, which regulates the body's internal clock.

NPAS2 forms a heterodimer with BMAL1, another circadian protein, and this complex binds to E-box elements in the promoter region of target genes to activate their transcription. The NPAS2-BMAL1 complex is negatively regulated by the proteins PER and CRY.

Clinical significance

Mutations in the NPAS2 gene have been associated with seasonal affective disorder, bipolar disorder, and major depressive disorder. In addition, some studies have suggested a link between NPAS2 and susceptibility to cancer, particularly breast cancer.

See also

• Circadian rhythm
• Transcription factor
• BMAL1
• PER protein
• CRY protein