Research Topics
Species | James StockandSummaryAffiliation: University of Texas Health Science Center Country: USA Publications
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Publications
Differential effects of protein kinase C on the levels of epithelial Na+ channel subunit proteinsJ D Stockand
Department of Physiology, University of Texas Health Science Center, San Antonio 78229, USA
J Biol Chem 275:25760-5. 2000..These results imply a PKC-dependent, long term decrease in Na(+) reabsorption...- S-adenosyl-L-homocysteine hydrolase is necessary for aldosterone-induced activity of epithelial Na(+) channelsJ D Stockand
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78284, USA
Am J Physiol Cell Physiol 281:C773-85. 2001..Thus aldosterone-induced SAHHase activity plays a critical role in shifting ENaC from a gating mode with short open and closed times to one with longer open and closed times... - Purinergic inhibition of ENaC produces aldosterone escapeJames D Stockand
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 3900, USA
J Am Soc Nephrol 21:1903-11. 2010..These data suggest that control of ENaC by purinergic signaling is necessary for aldosterone escape... - New ideas about aldosterone signaling in epitheliaJames D Stockand
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio Texas 78229 3900, USA
Am J Physiol Renal Physiol 282:F559-76. 2002.... - Vasopressin regulation of renal sodium excretionJames D Stockand
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229 3900, USA
Kidney Int 78:849-56. 2010.... - Collecting duct-specific endothelin B receptor knockout increases ENaC activityVladislav Bugaj
Department of Physiology, University of Texas Health Sciences Center, San Antonio, Texas 78229, USA
Am J Physiol Cell Physiol 302:C188-94. 2012.... - Insight toward epithelial Na+ channel mechanism revealed by the acid-sensing ion channel 1 structureJames D Stockand
Department of Physiology, University of Texas Health Science Center, San Antonio, TX 78229 3900, USA
IUBMB Life 60:620-8. 2008..Experiments resulting from this comparison of cASIC1 and ENaC may help clarify unresolved issues related to ENaC architecture, and may help identify secondary structures and residues critical to ENaC function... - Dietary Na+ inhibits the open probability of the epithelial sodium channel in the kidney by enhancing apical P2Y2-receptor toneOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas, USA
FASEB J 24:2056-65. 2010..The studies indicate a key role of the apical ATP/UTP-P2Y(2)-receptor system in the inhibition of ENaC P(o) in the ASDN in response to an increase in Na(+) intake, thereby contributing to NaCl homeostasis and blood pressure regulation... - Fluorescence resonance energy transfer analysis of subunit stoichiometry of the epithelial Na+ channelAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA
J Biol Chem 279:27729-34. 2004..The current results as a whole, thus, are most consistent with a higher ordered channel possibly with a 3alpha:3beta:3gamma stoichiometry... - Intrinsic voltage dependence of the epithelial Na+ channel is masked by a conserved transmembrane domain tryptophanOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229 3900, USA
J Biol Chem 284:25512-21. 2009..We conclude that the conserved Trp at the base of TM1 in ENaC/Deg channels protects against voltage by masking an inhibitory allosteric or pore block mechanism, which decreases activity in response to intracellular Na+... - A region directly following the second transmembrane domain in gamma ENaC is required for normal channel gatingRachell E Booth
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229, USA
J Biol Chem 278:41367-79. 2003..Similar to deletion of Gln573-Pro600, deletion of Gln573-Arg583 but not Thr584-Pro600 decreased ENaC activity. The current results demonstrate that residues within Gln573-Arg583 of gammaENaC are necessary for normal channel gating... - Rapid translocation and insertion of the epithelial Na+ channel in response to RhoA signalingOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229, USA
J Biol Chem 281:26520-7. 2006..Phosphatidylinositol 4,5-biphosphate produced by activated phosphatidylinositol 4-phosphate 5-kinase may play a role in targeting vesicles containing ENaC to the plasma membrane... - Direct activation of the epithelial Na(+) channel by phosphatidylinositol 3,4,5-trisphosphate and phosphatidylinositol 3,4-bisphosphate produced by phosphoinositide 3-OH kinaseQiusheng Tong
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA
J Biol Chem 279:22654-63. 2004..This represents a novel transduction pathway whereby growth factors, such as IGF-I, rapidly modulate target proteins independent of signaling elicited by kinases downstream of PI3K... - Identification of a functional phosphatidylinositol 3,4,5-trisphosphate binding site in the epithelial Na+ channelOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, 78229-3900, USA
J Biol Chem 280:37565-71. 2005..Phospholipid binding to this site is probably mediated by the positively charged amino acids within this track, with negatively charged and bulky residues also influencing specificity of interactions... - Quantifying RhoA facilitated trafficking of the epithelial Na+ channel toward the plasma membrane with total internal reflection fluorescence-fluorescence recovery after photobleachingOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, TX 78229 3900, USA
J Biol Chem 282:14576-85. 2007..The cytoskeleton is an established target for RhoA signaling. We conclude that RhoA, likely through effects on the cytoskeleton, promotes ENaC trafficking to the plasma membrane to increase channel membrane levels and activity... - Receptor tyrosine kinases mediate epithelial Na(+) channel inhibition by epidermal growth factorQiusheng Tong
Department of Physiology 7756, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
Am J Physiol Renal Physiol 288:F150-61. 2005..We conclude that EGF and other ligands for RTK decrease ENaC open probability by decreasing membrane PtdIns(4,5)P(2) levels... - The use of Chinese hamster ovary (CHO) cells in the study of ion channelsNikita Gamper
Department of Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio TX 78229, USA
J Pharmacol Toxicol Methods 51:177-85. 2005.... - Epithelial Na+ channel subunit stoichiometryAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center at San Antonio, 78229, USA
Biophys J 88:3966-75. 2005.... - Purinergic control of apical plasma membrane PI(4,5)P2 levels sets ENaC activity in principal cellsOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, 7703 Floyd Curl Dr, San Antonio TX 78229 3900, USA
Am J Physiol Renal Physiol 294:F38-46. 2008..Thus our results suggest that purinergic control of apical membrane PI(4,5)P(2) levels is a major regulator of ENaC activity in renal epithelial cells... - Activation of the epithelial Na+ channel in the collecting duct by vasopressin contributes to water reabsorptionVladislav Bugaj
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229 3900, USA
Am J Physiol Renal Physiol 297:F1411-8. 2009..In addition, our results support that the combined actions of vasopressin and aldosterone are required to achieve maximally activated ENaC... - Paracrine regulation of the epithelial Na+ channel in the mammalian collecting duct by purinergic P2Y2 receptor toneOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antoxio, Texas 78229 3900, USA
J Biol Chem 283:36599-607. 2008..P2Y2 receptor activation by nucleotides thus provides physiologically important regulation of ENaC and electrolyte handling in mammalian kidney... - Molecular determinants of PI(4,5)P2 and PI(3,4,5)P3 regulation of the epithelial Na+ channelOleh Pochynyuk
University of Texas Health Science Center, Department of Physiology, San Antonio, TX 78229, USA
J Gen Physiol 130:399-413. 2007..This argues that these phosphoinositides occupy distinct ligand-binding sites within ENaC to modulate open probability... - Subunit-dependent cadmium and nickel inhibition of acid-sensing ion channelsAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center at San Antonio, USA
Dev Neurobiol 67:97-107. 2007..The current study identifies ASIC as a novel target for the neurotoxic heavy metals Cd(2+) and Ni(2+)... - Functional polymorphisms in the alpha-subunit of the human epithelial Na+ channel increase activityQiusheng Tong
Department of Physiology, University of Texas Health Science Center at San Antonio, 78229-3900, USA
Am J Physiol Renal Physiol 290:F821-7. 2006..These results are consistent with the C618F and A663T polymorphisms leading to elevated ENaC activity with the possibility that they facilitate altered Na(+) handling by the kidney... - Ras couples phosphoinositide 3-OH kinase to the epithelial Na+ channelAlexander Staruschenko
University of Texas Health Science Center at San Antonio, Department of Physiology 7756, 7703 Floyd Curl Drive, San Antonio, TX 78229 3900, USA
Biochim Biophys Acta 1669:108-15. 2005..Here we demonstrate that K-Ras also interacts with ENaC through an, as yet, undetermined mechanism. We conclude that K-Ras enhances ENaC activity by localizing PI3-K near the channel and stimulating of PI3-K activity... - Rho small GTPases activate the epithelial Na(+) channelAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 3900, USA
J Biol Chem 279:49989-94. 2004..We conclude that RhoA activates ENaC via Rho kinase and subsequently activates PI(4)P 5-K with concomitant increases in PI(4,5)P(2) levels promoting channel insertion into the plasma membrane... - Ion channel regulation by Ras, Rho, and Rab small GTPasesOleh Pochynyuk
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229 3900, USA
Exp Biol Med (Maywood) 232:1258-65. 2007..We aim to provide critical insight into physiological control of ion channel function and the biological consequences of regulation of these important proteins by small, monomeric G proteins... - Subunit-specific modulation of KCNQ potassium channels by Src tyrosine kinaseNikita Gamper
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA
J Neurosci 23:84-95. 2003..Finally, experiments using cloned KCNQ2/3 channels, Src and M(1) muscarinic receptors, and sympathetic neurons demonstrated that the actions on KCNQ channels by Src and by muscarinic agonists use distinct mechanisms... - Acute regulation of the epithelial Na+ channel by phosphatidylinositide 3-OH kinase signaling in native collecting duct principal cellsAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229 3900, USA
J Am Soc Nephrol 18:1652-61. 2007..Together, these observations stress the importance of tight spatiotemporal coupling between PI3-K signaling and ENaC within the apical membrane of principal cells to the physiologic control of this ion channel... - Targeted degradation of ENaC in response to PKC activation of the ERK1/2 cascadeRachell E Booth
Department of Physiology, University Health Science Center, San Antonio, Texas 78229-3900, USA
Am J Physiol Renal Physiol 284:F938-47. 2003..Moreover, proteosome inhibitors (MG-132 and lactacystin) reversed PKC effects on this protected pool of gamma-ENaC. Thus PKC signaling via MAPK1/2 cascade activation in A6 cells promotes degradation of gamma-ENaC... - Functional reconstitution of the human epithelial Na+ channel in a mammalian expression systemAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center at San Antonio, USA
Methods Mol Biol 337:3-13. 2006..Here, we describe investigation of the human epithelial Na+ channel heterologously expressed in Chinese hamster ovary cells... - Identification of cytoplasmic domains within the epithelial Na+ channel reactive at the plasma membraneEunan Hendron
Department of Physiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-2900, USA
J Biol Chem 277:34480-8. 2002..We hypothesize that these newly identified domains play a role in modulating ENaC activity... - Ras activates the epithelial Na(+) channel through phosphoinositide 3-OH kinase signalingAlexander Staruschenko
University of Texas Health Science Center at San Antonio, Department of Physiology, San Antonio, Texas 78229-3900, USA
J Biol Chem 279:37771-8. 2004..Constitutively active PI3K activated ENaC independent of K-Ras with the effects of PI3K and K-Ras on ENaC not being additive. We conclude that K-Ras activates ENaC via the PI3K cascade... - Regulation of the epithelial Na+ channel by endothelin-1 in rat collecting ductVladislav Bugaj
Department of Physiology 7756, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229 3900, USA
Am J Physiol Renal Physiol 295:F1063-70. 2008..These findings may provide a potential mechanism for the natriuresis observed in vivo in response to ET-1, as well as a potential cause for the salt-sensitive hypertension found in animals with impaired endothelin signaling... - Regulation of epithelial Na+ channel activity by conserved serine/threonine switches within sorting signalsAlexander Staruschenko
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229 3900, USA
J Biol Chem 280:39161-7. 2005..These results demonstrate that the overlapping PY and YXXphi motifs in ENaC are, in some instances, capable of independent function and that the Ser/Thr just preceding and within these domains impact this function... - Activation of mitogen-activated protein kinase (mitogen-activated protein kinase/extracellular signal-regulated kinase) cascade by aldosteroneEunan Hendron
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio 78229-3900, USA
Mol Biol Cell 13:3042-54. 2002..The result of such a genomic mechanism is that peak activation of the MAPK cascade by adrenal corticosteroids is delayed but prolonged... - Regulation of the epithelial Na+ channel (ENaC) by phosphatidylinositidesOleh Pochynyuk
Dept. of Physiology, Univ. of Texas Health Science Center, 7703 Floyd Curl Dr, San Antonio, TX 78229-3900, USA
Am J Physiol Renal Physiol 290:F949-57. 2006..The putative PIP(3) binding site in ENaC involved in direct regulation of channel membrane levels has not yet been identified... - Aldosterone stimulates proliferation of cardiac fibroblasts by activating Ki-RasA and MAPK1/2 signalingJames D Stockand
Department of Physiology, University of Texas Health Science Center, San Antonio 78229, USA
Am J Physiol Heart Circ Physiol 284:H176-84. 2003..Activation of cardiac fibroblasts through such a cascade may play a role in the pathological actions exerted by aldosterone on the heart... - AldosteroneRachell E Booth
Department of Physiology, University of Texas Health Science Center San Antonio, San Antonio, Texas 78229 3900, USA
Adv Physiol Educ 26:8-20. 2002.... - Nonselective cation transport in native esophageal epitheliaMouhamed S Awayda
Dept of Physiology, SL 39, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
Am J Physiol Cell Physiol 287:C395-402. 2004..Moreover, our data are consistent with a potential role of ENaC subunits in the formation of a native nonselective cation channel... - Epithelial sodium channels are activated by furin-dependent proteolysisRebecca P Hughey
Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
J Biol Chem 279:18111-4. 2004..Channel activity in furin-deficient cells was rescued by expression of furin. Our data provide the first example of a vertebrate ion channel that is a substrate for furin and whose activity is dependent on its proteolysis... - Serum- and glucocorticoid-regulated kinase 1 regulates ubiquitin ligase neural precursor cell-expressed, developmentally down-regulated protein 4-2 by inducing interaction with 14-3-3Vivek Bhalla
Division of Nephrology, Department of Medicine, University of California-San Francisco, San Francisco, CA 94143-0532, USA
Mol Endocrinol 19:3073-84. 2005..These results demonstrate a novel, physiologically significant role for 14-3-3 proteins in modulating ubiquitin ligase-dependent pathways in the control of epithelial ion transport... - Regulation of Na+ transport by aldosterone: signaling convergence and cross talk between the PI3-K and MAPK1/2 cascadesQiusheng Tong
Dept. of Chemistry and Biochemistry, Texas State Univ, 601 University Dr, CHEM 216, San Marcos, TX, USA
Am J Physiol Renal Physiol 286:F1232-8. 2004.... - Preserving salt: in vivo studies with Sgk1-deficient mice define a modern role for this ancient proteinJames D Stockand
Am J Physiol Regul Integr Comp Physiol 288:R1-3. 2005
Research Grants
- Regulation of ENaC by phosphatidylinositide 3-kinase and phospholipidsJames D Stockand; Fiscal Year: 2010..The current proposal continues our investigation of the cellular and molecular mechanisms controlling ENaC activity in response to aldosterone. ..
- Stoichiometry and modular retrieval of ENaCJames Stockand; Fiscal Year: 2009..This research will provide critical insight about the molecualr architecture of ENaC and regulation of this important channel. ..
- Regulation of ENaC by phosphatidylinositide 3-kinase and phospholipidsJames Stockand; Fiscal Year: 2009..The current proposal continues our investigation of the cellular and molecular mechanisms controlling ENaC activity in response to aldosterone. ..
- Epithelial Na channel (ENaC) polymorphisms in hyptertentionJames Stockand; Fiscal Year: 2007..Preliminary results support the feasibility of this investigation and suggest that this line of inquiry will yield significant and novel findings. ..
- Stoichiometry and modular retrieval of ENaCJames Stockand; Fiscal Year: 2007..This research will provide critical insight about the molecular architecture of ENaC and regulation of this important channel. ..
- Regulation of the epithelial Na+ channel by Ras and SgkJames Stockand; Fiscal Year: 2006....
- Regulation of renal Na handling in the collecting duct by local purinergic toneJames D Stockand; Fiscal Year: 2010..The current proposal investigates the cellular and molecular mechanisms underlying renal salt handling particularly at the distal nephron, the location where systemic salt and water balance is fine-tuned in humans. ..