title: Disease-causing V(2) vasopressin receptors are retained in different compartments of the early secretory pathway.
abstract: The G protein-coupled V(2) vasopressin receptor is crucially involved in water reabsorption in the renal collecting duct. Mutations in the human V(2) vasopressin receptor gene cause nephrogenic diabetes insipidus. Many of the disease-causing mutants are retained intracellularly by the quality control system of the early secretory pathway. It was previously thought that quality control system is restricted to the endoplasmic reticulum (ER). Here, we have examined the retention mechanisms of eight V(2) vasopressin receptor mutants. We show that mutants L62P, DeltaL62-R64 and S167L are trapped exclusively in the ER. In contrast, mutants R143P, Y205C, InsQ292, V226E and R337X reach the ER/Golgi intermediate compartment (ERGIC) and are rerouted to the ER. The ability of the mutant receptors to reach the ERGIC is independent of their expression levels. Instead, it is determined by their folding state. Mutant receptors in the ERGIC may be sorted into retrograde transport vesicles by an interaction of an RXR motif in the third intracellular loop with the coatomer complex I. Our data show that disease-causing mutants of a particular membrane protein may be retained in different compartments of the early secretory pathway and that the folding states of the proteins determine their retention mechanism.
authors.affiliation: Forschungsinstitut für Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Hermosilla
authors.forename: Morad
authors.initials: M
authors.lastname: Oueslati
authors.forename: Ute
authors.initials: U
authors.lastname: Donalies
authors.forename: Eva
authors.initials: E
authors.lastname: Schönenberger
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.forename: Alexander
authors.initials: A
authors.lastname: Oksche
authors.forename: Walter
authors.initials: W
authors.lastname: Rosenthal
authors.forename: Ralf
authors.initials: R
authors.lastname: Schülein
mesh_terms: D000595:Amino Acid Sequence; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D021381:Protein Transport / Q000502:physiology; D017483:Receptors, Vasopressin / Q000235:genetics / Q000378:metabolism*
chemical_list: D017483:Receptors, Vasopressin