The Na+/H+ exchanger isoform 3 (NHE3) is a transport protein responsible for reabsorption of the majority of the filtered NaCl, NaHCO3 and, consequently, water, in renal proximal tubules. This transporter therefore plays an essential role regulating volume and acid-base homeostasis and determining blood pressure levels. The NHE3 activity modulation in response to stimuli is mediated by a number of molecular mechanisms, among them the redistribution of the transporter between the microdomains in the apical membrane of the proximal tubule. Although the physiological, pharmacological and pathophysiological importance of the subcellular distribution of NHE3 is very well established in the literature, the mechanisms involved in the translocation of this transporter from the base to the body of microvilli and vice versa remain unclear. Previously affinity chromatography and mass spectrometry experiments have shown that the myosin heavy chain type IIA, the motor protein involved in the transport of transporters to the plasma membrane, is physically associated with NHE3 in renal proximal tubules (unpublished data). Thus, this project aims to elucidate the molecular mechanisms involved in the redistribution of NHE3 between the proximal tubule microvilli in a situation of stimulation of sodium reabsorption in this segment of the nephron.
News published in Agência FAPESP Newsletter about the scholarship: