title: Intrarenal localization of the plasma membrane ATP channel pannexin1.
abstract: In the renal tubules, ATP released from epithelial cells stimulates purinergic receptors, regulating salt and water reabsorption. However, the mechanisms by which ATP is released into the tubular lumen are multifaceted. Pannexin1 (Panx1) is a newly identified. ubiquitously expressed protein that forms connexin-like channels in the plasma membrane, which have been demonstrated to function as a mechanosensitive ATP conduit. Here, we report on the localization of Panx1 in the mouse kidney. Using immunofluorescence, strong Panx1 expression was observed in renal tubules, including proximal tubules, thin descending limbs, and collecting ducts, along their apical cell membranes. In the renal vasculature, Panx1 expression was localized to vascular smooth muscle cells in renal arteries, including the afferent and efferent arterioles. Additionally, we tested whether Panx1 channels expressed in renal epithelial cells facilitate luminal ATP release by measuring the ATP content of urine samples freshly collected from wild-type and Panx1(-/-) mice. Urinary ATP levels were reduced by 30% in Panx1(-/-) compared with wild-type mice. These results suggest that Panx1 channels in the kidney may regulate ATP release and via purinergic signaling may participate in the control of renal epithelial fluid and electrolyte transport and vascular functions.
authors.affiliation: Department of Physiology and Biophysics, Univ. of Southern California, Los Angeles, CA 90033, USA.
authors.forename: Fiona
authors.initials: F
authors.lastname: Hanner
authors.forename: Lisa
authors.initials: L
authors.lastname: Lam
authors.forename: Mien T X
authors.initials: MT
authors.lastname: Nguyen
authors.forename: Alan
authors.initials: A
authors.lastname: Yu
authors.forename: János
authors.initials: J
authors.lastname: Peti-Peterdi
mesh_terms: D000255:Adenosine Triphosphate / Q000652:urine*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D017630:Connexins; D007473:Ion Channels; D009419:Nerve Tissue Proteins; C503631:Panx1 protein, mouse; D000255:Adenosine Triphosphate