Related Experiment Video
Updated: May 28, 2026

Isolation of Glomeruli and In Vivo Labeling of Glomerular Cell Surface Proteins
Published on: January 18, 2019
Podocyte Protein, Nephrin, Is a Substrate of Protein Tyrosine Phosphatase 1B
Lamine Aoudjit1, Ruihua Jiang, Tae Hoon Lee
1Division of Nephrology, Department of Medicine, McGill University, Montreal, QC, Canada H3A 2B4.
Abstract:
Glomerular podocytes are critical for the barrier function of the glomerulus in the kidney and their dysfunction causes protein leakage into the urine (proteinuria). Nephrin is a key podocyte protein, which regulates the actin cytoskeleton via tyrosine phosphorylation of its cytoplasmic domain. Here we report that two protein tyrosine phosphatases, PTP1B and PTP-PEST negatively regulate nephrin tyrosine phosphorylation. PTP1B directly binds to and dephosphorylates nephrin, while the action of PTP-PEST is indirect. The two phosphatases are also upregulated in the glomerulus in the rat model of puromycin aminonucleoside nephrosis. Both overexpression and inhibition of PTP1B deranged the actin cytoskeleton in cultured mouse podocytes. Thus, protein tyrosine phosphatases may affect podocyte function via regulating nephrin tyrosine phosphorylation.
Related Concept Videos
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Nephrons
Glomerular Filtration: Net Filtration Pressure
GBHP, with an average value of 55 mmHg, promotes filtration by pushing water and solutes through the filtration membrane. This is balanced by two opposing forces: CHP, a "back pressure" exerted against the filtration membrane by fluid already in the capsular space and renal tubule,...
Nephrotic Syndrome II : Assessment and Medical Management
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...

