Anion Exchanger 1 Interacts with Nephrin in Podocytes

Autor: Seth L. Alper, Simone M. Blattner, Timothy J. Satchwell, Mark T. Young, Nicola B. Kampik, Tibor Toth, Graham White, Mark D. Parker, Rosalind C. Williamson, Moin A. Saleem, Lan Ni, Carsten A. Wagner, Fiona Wu, Ashley M. Toye
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Adult
medicine.medical_specialty
Renal glomerulus
Xenopus
Kidney Glomerulus
Molecular Sequence Data
030232 urology & nephrology
Fluorescent Antibody Technique
Protein Serine-Threonine Kinases
urologic and male genital diseases
Podocyte
Nephrin
03 medical and health sciences
Mice
0302 clinical medicine
Internal medicine
Anion Exchange Protein 1
Erythrocyte
Two-Hybrid System Techniques
medicine
Albuminuria
Animals
Humans
Amino Acid Sequence
Cells
Cultured
030304 developmental biology
0303 health sciences
Kidney
biology
urogenital system
Podocytes
Glomerular basement membrane
Membrane Proteins
General Medicine
female genital diseases and pregnancy complications
3. Good health
Cell biology
medicine.anatomical_structure
Endocrinology
Basic Research
Membrane protein
Nephrology
Slit diaphragm
biology.protein
Female
Signal transduction
Zdroj: JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY
Popis: The central role of the multifunctional protein nephrin within the macromolecular complex forming the glomerular slit diaphragm is well established, but the mechanisms linking the slit diaphragm to the cytoskeleton and to the signaling pathways involved in maintaining the integrity of the glomerular filter remain incompletely understood. Here, we report that nephrin interacts with the bicarbonate/chloride transporter kidney anion exchanger 1 (kAE1), detected by yeast two-hybrid assay and confirmed by immunoprecipitation and co-localization studies. We confirmed low-level glomerular expression of kAE1 in human and mouse kidneys by immunoblotting and immunofluorescence microscopy. We observed less kAE1 in human glomeruli homozygous for the NPHS1(FinMaj) nephrin mutation, whereas kAE1 expression remained unchanged in the collecting duct. We could not detect endogenous kAE1 expression in NPHS1(FinMaj) podocytes in primary culture, but heterologous re-introduction of wild-type nephrin into these podocytes rescued kAE1 expression. In kidneys of Ae1(-/-) mice, nephrin abundance was normal but its distribution was altered along with the reported kAE1-binding protein integrin-linked kinase (ILK). Ae1(-/-) mice had increased albuminuria with glomerular enlargement, mesangial expansion, mesangiosclerosis, and expansion of the glomerular basement membrane. Glomeruli with ILK-deficient podocytes also demonstrated altered AE1 and nephrin expression, further supporting the functional interdependence of these proteins. These data suggest that the podocyte protein kAE1 interacts with nephrin and ILK to maintain the structure and function of the glomerular basement membrane.
Databáze: OpenAIRE
Externí odkaz: