SLC9A9
Description
The SLC9A9 (solute carrier family 9 member A9) is a protein-coding gene located on chromosome 3.
SLC9A9, also known as Na+/H+ exchanger 9, is an endosomal Na+, K+/H+ antiporter that mediates the electroneutral exchange of endosomal luminal H+ for a cytosolic Na+ or K+. By facilitating proton efflux, SLC9A9 counteracts the acidity generated by vacuolar (V)-ATPase, limiting luminal acidification. It regulates organellar pH, impacting endosome maturation and endocytic trafficking of plasma membrane receptors and neurotransporters. This protein promotes the recycling of transferrin receptors to the cell surface, facilitating iron uptake in the brain. It regulates synaptic transmission by controlling the luminal pH of axonal endosomes. Furthermore, SLC9A9 regulates phagosome lumenal pH, affecting phagosome maturation and microbicidal activity in macrophages. It can also be active at the cell surface of specialized cells, using the high K+ concentration of endolymph to regulate intracellular pH.
SLC9A9 is also known as AUTS16, NHE9.
Associated Diseases
- colorectal cancer
- glioblastoma
- isolated asymptomatic elevation of creatine phosphokinase
- plasma fibronectin deficiency
- pentosuria
