Functions as an integral cofactor in cell pH regulation by controlling plasma membrane-type Na(+)/H(+) exchange activity. Promotes the maturation, transport, cell surface stability and exchange activity of SLC9A1/NHE1 at the plasma membrane. Promotes the induction of hematopoietic stem cell differentiation toward megakaryocytic lineage. Essential for the coupling of ERK cascade activation with the expression of ETS family genes in megakaryocytic differentiation. Also involved in granulocytic differentiation in a ERK-dependent manner. Inhibits the phosphatase activity of calcineurin.
Subcellular locations: Nucleus, Cytoplasm, Membrane, Cell membrane, Cell projection, Lamellipodium, Cell projection, Ruffle membrane
Colocalizes with SLC9A1 at the plasma membrane.
Expressed in mature megakaryocytes and polymorphonuclear granulocytes (at protein level). Abundantly expressed in heart. Also expressed at a lower level in adult testis and salivary gland, and in the placenta.