Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, the kidney analog of the erythrocyte anion exchanger, band 3, served as the first example of an anion translocating membrane protein in a nucleated cell type to be localized at the ultrastructural level. Kidney band 3 was found to be confined to the basolateral membrane of the intercalated cells in the human collecting duct. The immunogold label displayed a striking non-uniform distribution along the basolateral plasma membrane with a preferential concentration at pleated areas of the membrane surface. The pleated portions are suggested to represent specialized subdomains to which the band 3 analog might be restricted by linkage via ankyrin to the spectrin-based membrane cytoskeleton. The immunolabel did not extend apically to the level of the zonula adherens and zonula occludens indicating that tight junctions might not be important for maintaining the polarized distribution of this integral membrane protein. Association of antibody label with the rough endoplasmic reticulum and other types of cytoplasmic membranes indicate pathways in the biosynthesis and degradation of this anion exchanger.
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PMID:Restriction of the human kidney band 3-like anion exchanger to specialized subdomains of the basolateral plasma membrane of intercalated cells. 332 92

The turtle urinary bladder serves as a model for collecting duct functions in the mammalian kidney. The epithelium of both the turtle bladder and the mammalian collecting duct can generate a steep gradient for H+ ions between blood and urine. Secretion of H+ into the urine is coupled to a basolateral efflux of HCO-3 that appears to be exchanged mainly against Cl-. Here we show that approximately 80% of the dark cells of the bladder contain a 110,000 relative molecular weight (Mr) analogue of the turtle erythrocyte anion exchanger, band 3. The band 3 analogue is confined to the basolateral cell surface and is absent from the apical membrane. A minor population of the dark cells (approximately 20%), which have been previously suggested to represent reverse cells that are involved in HCO-3 secretion rather than absorption, appears not to express a band 3-like anion exchanger, at either the apical or the basolateral membrane. The bladder band 3 protein is colocalized with actin and isoforms of ankyrin (200,000 Mr) and spectrin (230,000 Mr) along the basolateral membrane. Linkage of band 3 via ankyrin to the spectrin-actin lattice may restrict this anion exchanger to the basolateral membrane surface. In view of our previous observation of a band 3-like anion exchanger in the collecting duct epithelium of the rat kidney, these findings point to a common molecular basis for acid-base transport in the mammalian collecting duct and the reptilian urinary bladder.
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PMID:Band 3 is the basolateral anion exchanger of dark epithelial cells of turtle urinary bladder. 355 10