The Na-K-Cl cotransporter plays a vital role in transepithelial salt transport and in regulation of blood pressure. The Na-K-Cl cotransporters, NKCC1 and NKCC2, are key elements of net transport in the mammalian renal epithelium: NKCC1 forms part of the final pathway of K+ secretion in the collecting duct, and NKCC2 is key in the process of NaCl reabsorption across the in the thick ascending limb of the loop of Henle (TAL) and distal tubule, where it is the site of action of diuretics such as furosemide. The goal of this project is to understand the mechanisms that underlie the function and regulation of the Na-K-Cl cotransporters in the mammalian kidney. The proposed studies will be carried out with isolated renal tubules as well as with recombinant NKCC1 and NKCC2 protein expressed in the HEK cell expression system. Specifically: 1) We will elucidate the molecular structure of NKCC1, directly addressing ion and inhibitor sites in the translocation pore;we will discover the functional consequence of newly discovered rare human mutations in NKCC1 and NKCC2;and we will examine regulation of NKCC1 in the collecting duct during flow-activated K+ secretion. 2) We will determine the molecular mechanism of NKCC2, focusing on the role that TM2 plays in determination of ion binding kinetics and stoichiometry, and we will discover if intracellular [Cl-] is the signal underlying NKCC2 regulation in the TAL. 3) We will determine the molecular mechanism by which phosphorylation in the NKCC N-termini regulate transport conformational change in the transporter.
Na-K-Cl cotransporters (NKCCs) are responsible for maintaining water and electrolyte balance in vertebrates, and play a central role in regulating blood pressure through their role of regulated salt reabsorption in the renal tubule. This research is directed to understanding the molecular machinery that enables NKCCs to carry out regulated and coordinated sodium, potassium and chloride movements and to understanding the ways in which these transporters are regulated in the mammalian kidney. By understanding the molecular structure of the proteins, the mechanics of their action, and the mechanisms of its regulation we will be better able to design diagnostic and therapeutic agents such as improved diuretics to treat diseases involving salt balance, including hypertension.
| Kim, Jun-Mo; Xu, Shuhua; Guo, Xiaoyun et al. (2018) Urinary bladder hypertrophy characteristic of male ROMK Bartter's mice does not occur in female mice. Am J Physiol Regul Integr Comp Physiol 314:R334-R341 |
| Gassaway, Brandon M; Petersen, Max C; Surovtseva, Yulia V et al. (2018) PKC? contributes to lipid-induced insulin resistance through cross talk with p70S6K and through previously unknown regulators of insulin signaling. Proc Natl Acad Sci U S A 115:E8996-E9005 |
| Gilder, Allison L; Chapin, Hannah C; Padovano, Valeria et al. (2018) Newly synthesized polycystin-1 takes different trafficking pathways to the apical and ciliary membranes. Traffic 19:933-945 |
| Barber, Karl W; Muir, Paul; Szeligowski, Richard V et al. (2018) Encoding human serine phosphopeptides in bacteria for proteome-wide identification of phosphorylation-dependent interactions. Nat Biotechnol 36:638-644 |
| Scholl, Ute I; Stölting, Gabriel; Schewe, Julia et al. (2018) CLCN2 chloride channel mutations in familial hyperaldosteronism type II. Nat Genet 50:349-354 |
| Barber, Karl W; Rinehart, Jesse (2018) The ABCs of PTMs. Nat Chem Biol 14:188-192 |
| Barber, Karl W; Miller, Chad J; Jun, Jay W et al. (2018) Kinase Substrate Profiling Using a Proteome-wide Serine-Oriented Human Peptide Library. Biochemistry 57:4717-4725 |
| Castañeda-Bueno, Maria; Arroyo, Juan Pablo; Zhang, Junhui et al. (2017) Phosphorylation by PKC and PKA regulate the kinase activity and downstream signaling of WNK4. Proc Natl Acad Sci U S A 114:E879-E886 |
| Mohler, Kyle; Aerni, Hans-Rudolf; Gassaway, Brandon et al. (2017) MS-READ: Quantitative measurement of amino acid incorporation. Biochim Biophys Acta Gen Subj 1861:3081-3088 |
| D'Lima, Nadia G; Khitun, Alexandra; Rosenbloom, Aaron D et al. (2017) Comparative Proteomics Enables Identification of Nonannotated Cold Shock Proteins in E. coli. J Proteome Res 16:3722-3731 |
Showing the most recent 10 out of 303 publications
