Dietary salt regulates ubiquitination and urinary excretion of Na-Cl cotransporter

Abstract

Background: Membranous localization of NCC is mandatory for its function at distal convoluted tubule. Post-translational modification like phosphorylation and ubiquitination are important for various membrane proteins for their membranous localization. It has previously been reported that phosphorylation of NCC increased its membranous localization. We previously reported, low salt diet increased and high salt diet decreased expression and phosphorylation of NCC in kidney.

Objectives: In this study, we investigated whether ubiquitination is involved in the mechanisms of NCC regulation by dietary salt.

Materials & Methods: We examined ubiquitination and urinary excretion of NCC from mice fed with low-, regular- and high-salt diet. Study was done at Tokyo Medical and Dental University,during the period of January, 2013 to March, 2013.

Results: We found that, high salt diet increased and low salt diet decreased ubiquitination of NCC, correlated well with their total NCC abundance in kidney. Urinary excretion of exosomal NCC was increased both under low and high salt diet.

Conclusion: These results clearly indicated that dietary salt regulates ubiquitination of Na-Cl cotransporter and its urinary excretion.

KYAMC Journal Vol. 9, No.-1, April 2018, Page 2-5