Related Experiment Video
Updated: Nov 21, 2025

Study of the Functions and Activities of Neuronal K-Cl Co-Transporter KCC2 Using Western Blotting
Published on: December 9, 2022
Magnesium and Calcium Homeostasis Depend on KCTD1 Function in the Distal Nephron
1Cutaneous Biology Research Center, Massachusetts General Hospital, Charlestown, MA 02129, USA; Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
Magnesium (Mg2+) homeostasis depends on active transcellular Mg2+ reuptake from urine in distal convoluted tubules (DCTs) via the Mg2+ channel TRPM6, whose activity has been proposed to be regulated by EGF. Calcium (Ca2+) homeostasis depends on paracellular reabsorption in the thick ascending limbs of Henle (TALs). KCTD1 promotes terminal differentiation of TALs/DCTs, but how its deficiency affects urinary Mg2+ and Ca2+ reabsorption is unknown. Here, this study shows that DCT1-specific KCTD1 inactivation leads to hypomagnesemia despite normal TRPM6 levels because of reduced levels of the sodium chloride co-transporter NCC, whereas Mg2+ homeostasis does not depend on EGF. Moreover, KCTD1 deficiency impairs paracellular urinary Ca2+ and Mg2+ reabsorption in TALs because of reduced NKCC2/claudin-16/-19 and increased claudin-14 expression, leading to hypocalcemia and consequently to secondary hyperparathyroidism and progressive metabolic bone disease. Thus, KCTD1 regulates urinary reabsorption of Mg2+ and Ca2+ by inducing expression of NCC in DCTs and NKCC2/claudin-16/-19 in TALs.
Related Concept Videos
Skeleton and Calcium Homeostasis
Reabsorption and Secretion in the DCT and Collecting Duct
The distal...
Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion
Reabsorption and Secretion in the Loop of Henle
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
Reabsorption and Secretion in the PCT
Transport mechanisms involving sodium ions (Na+) contribute significantly to solute reabsorption. These mechanisms include symport and antiport processes.
A key example is the...

