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)

Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play a key role in docking and fusion of intracellular transport vesicles and may regulate apical and basolateral membrane protein delivery in epithelial cells. In a previous study, syntaxin 3 (a target SNARE) protein was detectable in the kidney only in intercalated cells. We now report a more widespread distribution of syntaxin 3 in a variety of renal epithelial cells after antigen retrieval. Sections of rat kidney were treated with SDS and incubated with antisyntaxin 3 antibodies. Strong basolateral membrane staining was seen in descending and ascending thin limbs of Henle, thick ascending limbs of Henle, the macula densa, distal and connecting tubules, and all cells of the collecting duct including A- and B-intercalated cells. The papillary surface epithelium and the transitional epithelium of the ureter were also stained, but proximal tubules were negative. Western blotting revealed a strong signal at 37 kDa in all regions, and the antigen was restricted to membrane fractions. SDS treatment was not necessary to reveal syntaxin 3 in intercalated cells. These data show that syntaxin 3 might be involved in basolateral trafficking pathways in most renal epithelial cell types. The exclusive basolateral location of syntaxin 3 in situ, however, contrasts with the apical location of this SNARE protein in some kidney epithelial cells in culture.
 ...
PMID:Antigen retrieval reveals widespread basolateral expression of syntaxin 3 in renal epithelia. 1183 35

ROMK potassium channels are present in the cortical collecting duct (CCD) of the kidney and serve as apical exit pathways for K+ secretion in this nephron segment. K+ secretion in the CCD is regulated by multiple factors. In this study, we show that syntaxin 1A, but not syntaxin 3 or 4, inhibited whole cell ROMK currents in Xenopus laevis oocytes. Syntaxin 1A, but not syntaxin 3 or 4, interacted with the COOH-terminal cytoplasmic domain of ROMK in intro. Coexpression with synaptobrevin 2 reversed inhibition of whole cell ROMK currents by syntaxin 1A. In excised inside-out membranes of oocytes, application of fusion proteins containing the cytoplasmic region of syntaxin 1A to the cytoplasmic face caused a dose-dependent inhibition of ROMK. We further examined regulation of the K+ channels in the CCD by syntaxin 1A. Application of botulinum toxin C1 to the excised inside-out membranes of the CCD caused an increase in the activity of K+ channels. In contrast, application of toxin B had no effects. These results suggest that syntaxin 1A causes a tonic inhibition of the K+ channels in the apical membrane of the CCD. Binding of synaptobrevin 2 to syntaxin 1A during docking and fusion of transport vesicles to the plasma membranes of CCD may lead to activation of these channels.
 ...
PMID:Inhibition of ROMK potassium channel by syntaxin 1A. 1545 95