HINT, also known as Histidine triad nucleotide-binding protein 1 and adenosine 5'-monophosphoramidase, is an enzyme that in humans is encoded by the HINT1 gene. HINT1 functions as a scaffolding protein that modulates transcriptional activation, while it also hydrolyzes purine nucleotide phosphoramidates with a single phosphate group.
In the LysRS-Ap4A-MITF signaling pathway, HINT1 prevents the MITF transcriptional activity by direct association. It is also a haploinsufficient tumor suppressor gene, inhibiting the Wnt/β-catenin pathway in colon cancer cells and microphthalmia-associated transcription factor (MITF) activity in human mast cells. HINT1 is released from MITF by diadenosine tetraphosphate (Ap4A), produced by LysRS when pathways are activated. Mutations in this gene can cause autosomal recessive neuromyotonia and axonal neuropathy.
While the specific mechanisms of HINT1 are not completely understood, this protein is involved in the nervous system. HINT1 binds to signaling proteins in nerve cells called receptors that relay signals affecting nervous system function. HINT1 is known to stabilize the interaction of different receptors to regulate the effects of their signaling.
The HINT1 protein is also involved in cell death. When cells are no longer needed, HINT1 causes apoptosis, helping to conserve energy by removing unneeded cells and halting their activity. HINT1 can prevent cells from growing or dividing too rapidly, enabling your body to maintain control over cell growth.