title: Concerted action of associated proteins in the regulation of TRPV5 and TRPV6.
abstract: Ca(2+) is an essential ion in all organisms and many physiological functions in the body rely on the exact maintenance of the Ca(2+) balance. The epithelial Ca(2+) channels TRPV5 [TRP (transient receptor potential) vanilloid 5] and TRPV6 are the most Ca(2+)-selective members of the TRP superfamily and are generally considered as the gatekeepers of Ca(2+) entry across epithelia. TRPV5 is involved in Ca(2+) reabsorption from pro-urine, while TRPV6 has an essential role in intestinal Ca(2+) uptake. These channels are the prime targets of calciotropic hormonal regulation, including vitamin D and parathyroid hormone. In addition, extra- and intra-cellular signalling by associated proteins and Ca(2+) itself play key roles in TRPV5 and TRPV6 regulation. In this paper, we describe the present understanding of the concerted action of calbindin-D(28k), klotho and BSPRY (B-box and SPRY-domain-containing protein) at different levels throughout the epithelial cell to control Ca(2+) influx at the luminal entry gate.
authors.affiliation: Department of Physiology, NCMLS (Nijmegen Centre for Molecular Life Sciences), Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, The Netherlands.
authors.forename: J P H
authors.initials: JP
authors.lastname: Schoeber
authors.forename: J G J
authors.initials: JG
authors.lastname: Hoenderop
authors.forename: R J M
authors.initials: RJ
authors.lastname: Bindels
mesh_terms: D000818:Animals; D064026:Calbindins; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D005786:Gene Expression Regulation; D005966:Glucuronidase / Q000378:metabolism; D006801:Humans; D007477:Ions; D000090265:Klotho Proteins; D008954:Models, Biological; D010281:Parathyroid Hormone / Q000378:metabolism; D017434:Protein Structure, Tertiary; D064030:S100 Calcium Binding Protein G / Q000737:chemistry; D015398:Signal Transduction; D050916:TRPV Cation Channels / Q000502:physiology*; D014807:Vitamin D / Q000737:chemistry
chemical_list: D064026:Calbindins; D015220:Calcium Channels; D007477:Ions; D010281:Parathyroid Hormone; D064030:S100 Calcium Binding Protein G; D050916:TRPV Cation Channels; C492239:TRPV5 protein, human; C422827:TRPV6 protein, human; D014807:Vitamin D; D005966:Glucuronidase; D000090265:Klotho Proteins; D002118:Calcium