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

Vasopressin regulates water and solute transport in the renal collecting duct. In addition to short-term regulation of aquaporin-2 trafficking, vasopressin also has long-term effects to regulate the abundances of aquaporins-2 and -3 and beta- and gamma-subunits of the epithelial sodium channel in collecting duct principal cells. To investigate further the direct and indirect long-term regulatory actions of vasopressin in the inner medullary collecting duct (IMCD), we used a proteomic approach [difference gel electrophoresis (DIGE) coupled with MALDI-TOF identification of differentially expressed protein spots]. DDAVP or vehicle was infused subcutaneously in Brattleboro rats for 3 days, and IMCD cells were purified from the inner medullas for proteomic analysis. Forty-three proteins were found to be regulated in response to vasopressin infusion, including 18 that were increased in abundance, 22 that were decreased, and 3 that were shifted in the gel, presumably because of posttranslational modification. Immunocytochemistry confirmed collecting duct expression of several of the proteins that were identified. Immunoblot analysis of nine of the proteins confirmed the changes seen by the DIGE method. Of these nine proteins, six were increased in response to DDAVP infusion: nitric oxide synthase-2 (NOS2), GRP78, heat shock protein-70, annexin II, glutaminase, and cathepsin D. The remaining three were decreased in response to DDAVP: aldehyde reductase I, adenylyl cyclase VI, and carbonic anhydrase II. The findings point to a role for vasopressin in the coordinate regulation of several determinants of nitric oxide levels (NOS2, arginase II, NADPH oxidase) and of proteins potentially involved in vasopressin escape (adenylyl cyclase VI and G protein-coupled receptor kinase 4).
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PMID:Proteomic analysis of long-term vasopressin action in the inner medullary collecting duct of the Brattleboro rat. 1453 64

Targeted positioning of water channel aquaporin-2 (AQP2) strictly regulates body water homeostasis. Trafficking of AQP2 to the apical membrane is critical to the reabsorption of water in renal collecting ducts. Recently, we have identified for the first time proteins which directly bind to AQP2: SPA-1, a GTPase-activating protein for Rap1, and cytoskeletal protein actin. Based on these findings, we have speculated the existence of a multiprotein complex which includes AQP2, SPA-1, and actin, for providing the mechanism which generates force and motion in AQP2 trafficking. To clarify the proteins comprising the complex, a large amount of AQP2-associated protein complex was isolated from the extract of rat kidney papilla using immunoaffinity column coupled with anti-AQP2 antibody and was analyzed by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition to SPA-1 and actin, 11 proteins were identified using this method: ionized calcium binding adapter molecule 2, myosin regulatory light chain smooth muscle isoforms 2-A and 2-B, alpha-tropomyosin 5b, annexin A2 and A6, scinderin, gelsolin, alpha-actinin 4, alpha-II spectrin, and myosin heavy chain nonmuscle type A. Our findings show for the first time an AQP2-binding multiprotein "force generator" complex. This multiprotein complex may provide the machinery of driving AQP2 movement.
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PMID:Identification of a multiprotein "motor" complex binding to water channel aquaporin-2. 1582 48

A proteome map of the most abundant proteins in the murine inner medullary collecting duct (mIMCD3) cell line was generated by 2-dimensional gel electrophoresis (2D-GE) combined with MALDI-TOF/TOF mass spectrometry. The 2-D model map identifies 77 distinct constitutive proteins and a total of 86 spots including isoforms. Protein identification was based on both peptide mass fingerprinting (MS) and peptide fragmentation (MS/MS) data. High confidence Mascot scores were obtained in the database search, due to the high quality and the number of MS/MS spectra which provided matching sequence information to the database. A functional classification of the identified proteins showed that a high proportion were stress proteins, such as heat shock proteins and proteins with anti-oxidant activity. Other proteins identified were involved in cytoskeletal maintenance, metabolism and energy generation, as well as in translation, transcription, RNA processing and other cell cycle processes. Exposure of the mIMCD3 cells to hyperosmotic stress using 600 mOsmol/kg NaCl or Urea or 700 mOsmol/kg NaCl-Urea (50:50) resulted in the greatest proteome upregulation in 700 mosM NaCl-Urea and the greatest downregulation in 600 mosM NaCl. Several proteins with molecular chaperone function were induced, such as alpha-B crystallin, two Hsp70 isoforms, the osmotic stress protein (Osp94), as well as aldose reductase. Additional isoforms of the translation elongation factors Eef2 and Eef1a1 were induced. Characterization of the phosphoproteome of mIMCD3 cells with a phosphoprotein-specific stain showed a significant proportion of the proteome was phosphorylated. Additionally, exposure of mIMCD3 cells to 600 mOsmol/kg NaCl hyperosmotic stress resulted in a 1.8-fold higher phosphorylation level of the most acidic isoform of the heat shock protein Hsp27 compared to its phosphorylation level under iso-osmotic conditions.
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PMID:Constitutive and inducible stress proteins dominate the proteome of the murine inner medullary collecting duct-3 (mIMCD3) cell line. 1671 11