NRH: Quinone Reductase activity results in the accumulation of endogenous dopamine in the retina

Dopamine quinone is substrate of the NRH: Quinone Reductase enzyme (QR2) in the retina. The capability of accumulates endogenous dopamine in a neural tissue explains the association of certain neuropsychiatric diseases with polymorphisms in the QR2 promoter that causes overexpression via loss of the capability to bind repressors. However, QR2 doubly reduce other small compounds present in neural and non-neural tissues, being its physiology tissue dependent. In this context, the function of the neurohormone melatonin and analogues in the active site of this multifunctional enzyme is discussed in this mini review.