The potential role of myosin motor proteins in mediating the subcellular distribution of NHE3 in the renal proximal tubule.

The potential role of myosin motor proteins in mediating the subcellular distribution of NHE3 in the renal proximal tubule. Am J Physiol Renal Physiol. 2019 Mar 13;: Authors: Crajoinas RO, Polidoro JZ, Girardi ACC Abstract Isoform 3 of the Na+/H+ exchanger (NHE3) is responsible for the majority of the reabsorption of NaCl, NaHCO3 and, consequently, water in the renal proximal tubule. As such, this transporter plays an essential role in acid-base balance, extracellular fluid volume homeostasis and determining systemic arterial blood pressure levels. NHE3 activity is modulated by a number of mechanisms, including the redistribution of the transporter between the body of the microvilli (where NHE3 is active) and the base of the microvilli (where NHE3 is less active). Although the physiological, pathophysiological and pharmacological importance of the subcellular distribution of NHE3 is well established, the exact mechanism whereby NHE3 is translocated along microvilli microdomains of the proximal tubule apical membrane is unknown. Nonmuscle myosin IIA and unconventional myosin VI move cargoes in anterograde and retrograde directions, respectively, and are known to redistribute along with NHE3 in the proximal tubule in response to a variety of natriuretic and anti-natriuretic stimuli, including stimulation or inhibition of the renin-angiotensin-system, high dietary sodium intake and high blood pressure. Therefore, this mini-review aims t...
Source: American Journal of Physiology. Renal Physiology - Category: Physiology Authors: Tags: Am J Physiol Renal Physiol Source Type: research