Characterization of Two Novel Missense Mutations in the AQP2 Gene Causing Nephrogenic Diabetes Insipidus

Here, we report the aquaporin 2 (AQP2) mutational analysis of a patient with nephrogenic diabetes insipidus heterozygote due to two novel missense mutations. Direct sequencing of DNA in the male patient revealed that he was compound heterozygote for two mutations in the AQP2 gene: a thymine-to-adenine transversion at position 450 (c.450T>A) in exon 2 and a guanine-to-thymine at nucleotide position 643 (c.643G>T) in exon 4. The double heterozygous 450T>A and 643G>T transversion causes the amino acid substitution D150E and G215C. Direct sequencing of exons 2 and 4 of the AQP2 gene from each of the parents revealed that the c.450T>A mutation was inherited from the father while the c.643G>T mutation was inherited from the mother. Analysis of AQP2 excretion demonstrated that no AQP2 was detectable in the urine of the proband, whereas normal AQP2 levels were measured in both parents. When expressed in renal cells, both proteins were retarded in the endoplasmic reticulum and no redistribution was observed after forskolin stimulation. Of note, homology modeling revealed that the two mutations involve two highly conserved residues providing important clues about the role of the wt residues in AQP2 stability and function

Deeply Inverted Electron-Hole Recombination in a Luminescent Antibody-Stilbene Complex

The blue-emissive antibody EP2-19G2 that has been elicited against trans-stilbene has unprecedented ability to produce bright luminescence and has been used as a biosensor in various applications. We show that the prolonged luminescence is not stilbene fluorescence. Instead, the emissive species is a charge-transfer excited complex of an anionic stilbene and a cationic, parallel π-stacked tryptophan. Upon charge recombination, this complex generates exceptionally bright blue light. Complex formation is enabled by a deeply penetrating ligand-binding pocket, which in turn results from a noncanonical interface between the two variable domains of the antibody

The Compartmentalized Bacteria of the Planctomycetes-Verrucomicrobia-Chlamydiae Superphylum Have Membrane Coat-Like Proteins

Compartmentalized bacteria have proteins that are structurally related to eukaryotic membrane coats, and one of these proteins localizes at the membrane of vesicles formed inside bacterial cells

Molecular architecture of the Nup84–Nup145C–Sec13 edge element in the nuclear pore complex lattice

Nuclear pore complexes (NPCs) facilitate all nucleocytoplasmic transport. These massive protein assemblies are modular, with a stable structural scaffold supporting more dynamically attached components. The scaffold is made from multiple copies of the heptameric Y complex and the heteromeric Nic96 complex. We previously showed that members of these core subcomplexes specifically share an ACE1 fold with Sec31 of the COPII vesicle coat, and we proposed a lattice model for the NPC based on this commonality. Here we present the crystal structure of the heterotrimeric 134-kDa complex of Nup84–Nup145C–Sec13 of the Y complex. The heterotypic ACE1 interaction of Nup84 and Nup145C is analogous to the homotypic ACE1 interaction of Sec31 that forms COPII lattice edge elements and is inconsistent with the alternative 'fence-like' NPC model. We construct a molecular model of the Y complex and compare the architectural principles of COPII and NPC lattices.National Institutes of Health (U.S.) (Grant GM77537)Pew Charitable Trusts (Scholar Award

Inner/Outer Nuclear Membrane Fusion in Nuclear Pore Assembly: Biochemical Demonstration and Molecular Analysis

The nuclear pore complex (NPC) is characterized by a long-lived membrane-lined channel connecting the inner and outer nuclear membranes. This stabilized membrane channel, within which the nuclear pore is built, has little evolutionary precedent. In this report we demonstrate and map the inner/outer nuclear membrane fusion in NPC assembly

Characterization of two novel missense mutations in the AQP2 gene causing nephrogenic diabetes insipidus.

Item does not contain fulltextHere, we report the aquaporin 2 (AQP2) mutational analysis of a patient with nephrogenic diabetes insipidus heterozygote due to two novel missense mutations. Direct sequencing of DNA in the male patient revealed that he was compound heterozygote for two mutations in the AQP2 gene: a thymine-to-adenine transversion at position 450 (c.450T>A) in exon 2 and a guanine-to-thymine at nucleotide position 643 (c.643G>T) in exon 4. The double heterozygous 450T>A and 643G>T transversion causes the amino acid substitution D150E and G215C. Direct sequencing of exons 2 and 4 of the AQP2 gene from each of the parents revealed that the c.450T>A mutation was inherited from the father while the c.643G>T mutation was inherited from the mother. Analysis of AQP2 excretion demonstrated that no AQP2 was detectable in the urine of the proband, whereas normal AQP2 levels were measured in both parents. When expressed in renal cells, both proteins were retarded in the endoplasmic reticulum and no redistribution was observed after forskolin stimulation. Of note, homology modeling revealed that the two mutations involve two highly conserved residues providing important clues about the role of the wt residues in AQP2 stability and function