High impact information on Trpv5

• Both channels retained their phenotype after exchanging the complete N termini, the C termini, or even both N and C termini, i.e. ECaC1 with the ECaC2 N or C terminus still showed the ECaC1 phenotype and vice versa [1].
• However, the kinetics of ECaC2 currents notably differ from ECaC1 currents [1].
• 1,25-dihydroxyvitamin D(3)-independent stimulatory effect of estrogen on the expression of ECaC1 in the kidney [2].
• In conclusion, this study suggests that 17beta-E(2) is positively involved in renal Ca(2+) reabsorption via the upregulation of ECaC1, an effect independent of 1,25-dihydroxyvitamin D(3) [2].
• Calcium transporter 1 and epithelial calcium channel messenger ribonucleic acid are differentially regulated by 1,25 dihydroxyvitamin D3 in the intestine and kidney of mice [3].

Biological context of Trpv5

• Mice in which the 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-OHase) gene was inactivated presented the same clinical phenotype as patients with PDDR and were used to study renal expression of the epithelial Ca2+ channel (ECaC1), the calbindins, Na+/Ca2+ exchanger (NCX1), and Ca2+-ATPase (PMCA1b) [4].
• Fast and slow inactivation kinetics of the Ca2+ channels ECaC1 and ECaC2 (TRPV5 and TRPV6). Role of the intracellular loop located between transmembrane segments 2 and 3 [1].
• These results suggest that 1alpha,25(OH)(2)D(3) directly modulates the gene expression of ECaC1 and ECaC2 together with PTH in the kidney of mice [5].
• Effects of CsA on the expression of calbindin-D28k, and two calcium channels in the apical membrane of the distal tubule, epithelial calcium channel (ECaC) and alpha1G-subunit of a voltage-dependent Ca channel (alpha1G), in the kidney were examined by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) [6].

Anatomical context of Trpv5

• We examined the expression of calcium transporter 1 (CaT1) and epithelial calcium channel (ECaC) mRNA in the duodenum and kidney of mice [3].

Associations of Trpv5 with chemical compounds

• 4. Ruthenium red is a potent blocker of ECaC activity [7].
• 1. The epithelial Ca(2+) channel (ECaC) family represents a unique group of Ca(2+)-selective channels that share limited homology to the ligand-gated capsaicin receptors, the osmolarity-sensitive channel OTRPC4, as well as the transient receptor potential family [7].
• In addition novel 1,25(OH)(2)D(3) target genes have been identified including the epithelial calcium channel, present in the proximal intestine and in the distal nephron [8].

Regulatory relationships of Trpv5

• Our data indicate that CaT1 and ECaC mRNA levels are differentially regulated by 1,25(OH)(2)D(3) in kidney and intestine and that there may be a specialized role for CaT1 in kidney in fetal and neonatal development [3].

Other interactions of Trpv5

• We report the phenotype of mice with targeted disruption of the Trpv6 (Trpv6 KO) epithelial calcium channel [9].
• In contrast, both duodenal Ca absorption and ECaC1 and ECaC2 mRNA abundance were lower in mice with X-linked hypophosphataemia ( Hyp) than in normal littermates [10].

Analytical, diagnostic and therapeutic context of Trpv5

• Southern blot analysis demonstrated that this family is restricted to two members, ECaC1 and ECaC2 (also named CaT1) [7].
• Using real-time quantitative PCR and immunohistochemical analyses, this study demonstrated that 17beta-E(2) treatment at pharmacologic doses increased renal mRNA levels of ECaC1, calbindin-D(28K), NCX1, and PMCA1b and increased the protein abundance of ECaC1 [2].

References