Project description:The urea channel Slc14a2 (or UT-A1) mediates vasopressin-regulated urea transport across the inner medullary collecting duct (IMCD). Previously, UT-A1 was found to present in a high molecular weight complex, suggesting UT-A1 is involved in certain protein-protein interactions. The present study sought to identify the proteins that interact with UT-A1 in this complex for a better understanding of how UT-A1 is regulated. Rat IMCD suspensions were treated with or without V2 receptor agonist, dDAVP, followed by in-cell crosslinking using BSOCOES and detergent solubilization. Immunoprecipitation using Dynabeads coated with UT-A1 specific antibody successfully pulled down the UT-A1 proteins. In-gel digestion protocol was carried out to prepare samples for liquid chromatographic mass spectrometry analysis of tryptic peptides using a Velos-Orbitrap mass spectrometer. The peptides passing stringent spectral quality thresholds were quantified (label-free) to identify those with (UTA-1 antibody/preimmune IgG) >4. A total of 128 UT-A1 interacting proteins were identified. Gene Ontology analysis maps the distribution of these proteins throughout major cell compartments: endoplasmic reticulum, Golgi, endosomes, cytosol and plasma membrane. Among them are four protein kinases (Cdc42bpb, Phkb, Camk2d, Mtor) that play roles in vasopressin-regulated phosphorylation of UT-A1. Non-label quantification was also performed to determine the stoichiometry of UT-A3 with UT-A1, the result does not support an oligomeric complex formation of UT-A1/A3. In conclusion, we have provided a refined list of UT-A1 binding proteins which can be useful for further analysis of the vasopressin signaling pathway in regulation of UT-A1 in IMCD.
Project description:Objective: We intended to explore the potential molecular mechanisms underlying cardiac conduction block inducted by UT-B deletion at the transcriptome level. Methods: The heart tissues were harvested from UT-B null mice and age-matched wild-type mice for lncRNA sequencing analysis. Based on the sequencing data, the differentially expressed mRNAs (DEMs) and lncRNAs (DELs) between UT-B knockout and control groups were identified, followed by function analysis and mRNA-lncRNA co-expression analysis. The miRNAs were predicted, and then the competing endogenous RNA (ceRNA) network was constructed. Results: UT-B deletion results in the aberrant expression of 588 lncRNAs and 194 mRNAs. These DEMs were significantly enriched in inflammation-related pathway. A lncRNA-mRNA co-expression network and a ceRNA network was constructed on the basis of the DEMs and DELs. C7 (complement C7)-NONMMUT137216.1 co-expression pair had the highest correlation coefficient in the co-expression network. NONMMUT140591.1 had the highest degree in ceRNA network and involved in ceRNA of NONMMUT140591.1-mmu-miR-298-5p-Gata5 (GATA binding protein 5). Conclusion: UT-B deletion may promote cardiac conduction block via inflammatory process. The ceRNA NONMMUT140591.1-mmu-miR-298-5p-Gata5 may be a potential molecular mechanism of UT-B knockout-induced cardiac conduction block.