Localization and topology of a urate transporter/channel, a galectin, in epithelium-derived cells

2001 ◽  
Vol 281 (6) ◽  
pp. C1926-C1939 ◽  
Author(s):  
Joshua Z. Rappoport ◽  
Michael S. Lipkowitz ◽  
Ruth G. Abramson
Keyword(s):  
Lipid Bilayers ◽  
Plasma Membranes ◽  
Kidney Cells ◽  
Madin Darby Canine Kidney ◽  
Urate Transporter ◽  
And Topology ◽  
Cell Surface Biotinylation ◽  
Cytoplasmic Side ◽  
Darby Canine Kidney ◽  
Canine Kidney

Recombinant protein produced from a cDNA cloned in our laboratory (UAT) functions in lipid bilayers as a urate transporter/channel. Because UAT is a galectin, a family of proteins presumed to be soluble, the localization and topology of UAT were assessed in living cells. UAT was targeted to plasma membrane in multiple epithelium-derived cell lines and, in polarized cells, was targeted to both apical and basolateral membranes. The amino and carboxy termini of UAT were both detected on the cytoplasmic side of plasma membranes, whereas cell surface biotinylation studies demonstrated that UAT is not merely a cytosolic membrane-associated protein but contains at least one extracellular domain. Madin-Darby canine kidney cells were shown both functionally and immunologically to contain an apparent homolog of UAT; however, transfection with UAT did not modify urate uptake. Because coimmunoprecipitation studies revealed that UAT is capable of forming both homo- and heteromultimers, it is proposed that monomers of endogenous channels are in part replaced by monomers of the protein expressed subsequent to transfection, thereby maintaining constancy of urate uptake at basal levels.

scholarly journals Polarized delivery of viral glycoproteins to the apical and basolateral plasma membranes of Madin-Darby canine kidney cells infected with temperature-sensitive viruses.

1985 ◽  
Vol 100 (1) ◽  
pp. 136-151 ◽  
Author(s):  
M J Rindler ◽  
I E Ivanov ◽  
H Plesken ◽  
D D Sabatini
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Plasma Membranes ◽  
Temperature Sensitive ◽  
Kidney Cells ◽  
Apical Surface ◽  
Nonpermissive Temperature ◽  
Madin Darby Canine Kidney ◽  
Darby Canine Kidney ◽  
Canine Kidney

The intracellular route followed by viral envelope glycoproteins in polarized Madin-Darby canine kidney cells was studied by using temperature-sensitive mutants of vesicular stomatitis virus (VSV) and influenza, in which, at the nonpermissive temperature (39.5 degrees C), the newly synthesized glycoproteins (G proteins) and hemagglutinin (HA), respectively, are not transported out of the endoplasmic reticulum. After infection with VSV and incubation at 39.5 degrees C for 4-5 h, synchronous transfer of G protein to the plasma membrane was initiated by shifting to the permissive temperature (32.5 degrees C). Immunoelectron microscopy showed that under these conditions the protein moved to the Golgi apparatus and from there directly to a region of the lateral plasma membrane near this organelle. G protein then seemed to diffuse progressively to basal regions of the cell surface and, only after it had accumulated in the basolateral domain, it began to appear on the apical surface near the intercellular junctions. The results of these experiments indicate that the VSV G protein must be sorted before its arrival at the cell surface, and suggest that passage to the apical domain occurs only late in infection when tight junctions are no longer an effective barrier. In complementary experiments, using the temperature-sensitive mutant of influenza, cultures were first shifted from the nonpermissive temperature (39.5 degrees C) to 18.5 degrees C, to allow entrance of the glycoprotein into the Golgi apparatus (see Matlin, K.S., and K. Simons, 1983, Cell, 34:233-243). Under these conditions HA accumulated in Golgi stacks and vesicles but did not reach the plasma membrane. When the temperature was subsequently shifted to 32.5 degrees C, HA rapidly appeared in discrete regions of the apical surface near, and often directly above, the Golgi elements, and later diffused throughout this surface. To ensure that the anti-HA antibodies had access to lateral domains, monolayers were treated with a hypertonic medium to dilate the intercellular spaces. Some labeling was then observed in the lateral plasma membranes soon after the shift, but this never increased beyond 1.0 gold particle/micron, whereas characteristic densities of labeling in apical surfaces soon became much higher (approximately 10 particles/micron). Our results suggest that the bulk of HA follows a direct pathway leading from the Golgi to regions of the apical surface close to trans-Golgi cisternae.

scholarly journals Inhibition by brefeldin A of protein secretion from the apical cell surface of Madin-Darby canine kidney cells.

1991 ◽  
Vol 266 (27) ◽  
pp. 17729-17732 ◽  
Author(s):  
S.H. Low ◽  
S.H. Wong ◽  
B.L. Tang ◽  
P. Tan ◽  
V.N. Subramaniam ◽  
...  
Keyword(s):  
Cell Surface ◽  
Protein Secretion ◽  
Apical Cell ◽  
Brefeldin A ◽  
Kidney Cells ◽  
Madin Darby Canine Kidney ◽  
Darby Canine Kidney ◽  
Canine Kidney

MST3 is involved in ENaC-mediated hypertension

2019 ◽  
Vol 317 (1) ◽  
pp. F30-F42
Author(s):  
Te-Jung Lu ◽  
Wei-Chih Kan ◽  
Sung-Sen Yang ◽  
Si-Tse Jiang ◽  
Sheng-Nan Wu ◽  
...  
Keyword(s):  
Kidney Cells ◽  
Hypertensive Rats ◽  
Madin Darby Canine Kidney ◽  
Spontaneously Hypertensive ◽  
Hypomorphic Mutation ◽  
And Oxidative Stress ◽  
Darby Canine Kidney ◽  
Canine Kidney

Liddle syndrome is an inherited form of human hypertension caused by increasing epithelial Na+ channel (ENaC) expression. Increased Na+ retention through ENaC with subsequent volume expansion causes hypertension. In addition to ENaC, the Na+-K+-Cl− cotransporter (NKCC) and Na+-Cl− symporter (NCC) are responsible for Na+ reabsorption in the kidneys. Several Na+ transporters are evolutionarily regulated by the Ste20 kinase family. Ste20-related proline/alanine-rich kinase and oxidative stress-responsive kinase-1 phosphorylate downstream NKCC2 and NCC to maintain Na+ and blood pressure (BP) homeostasis. Mammalian Ste20 kinase 3 (MST3) is another member of the Ste20 family. We previously reported that reduced MST3 levels were found in the kidneys in spontaneously hypertensive rats and that MST3 was involved in Na+ regulation. To determine whether MST3 is involved in BP stability through Na+ regulation, we generated a MST3 hypomorphic mutation and designated MST3+/− and MST3−/− mice to examine BP and serum Na+ and K+ concentrations. MST3−/− mice exhibited hypernatremia, hypokalemia, and hypertension. The increased ENaC in the kidney played roles in hypernatremia. The reabsorption of more Na+ promoted more K+ secretion in the kidney and caused hypokalemia. The hypernatremia and hypokalemia in MST3−/− mice were significantly reversed by the ENaC inhibitor amiloride, indicating that MST3−/− mice reabsorbed more Na+ through ENaC. Furthermore, Madin-Darby canine kidney cells stably expressing kinase-dead MST3 displayed elevated ENaC currents. Both the in vivo and in vitro results indicated that MST3 maintained Na+ homeostasis through ENaC regulation. We are the first to report that MST3 maintains BP stability through ENaC regulation.

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