@article {919, title = {DAAM2 Variants Cause Nephrotic Syndrome via Actin Dysregulation.}, journal = {Am J Hum Genet}, volume = {107}, year = {2020}, month = {2020 12 03}, pages = {1113-1128}, abstract = {

The discovery of >60 monogenic causes of nephrotic syndrome (NS) has revealed a central role for the actin regulators RhoA/Rac1/Cdc42 and their effectors, including the formin INF2. By whole-exome sequencing (WES), we here discovered bi-allelic variants in the formin DAAM2 in four unrelated families with steroid-resistant NS. We show that DAAM2 localizes to the cytoplasm in podocytes and in kidney sections. Further, the variants impair DAAM2-dependent actin remodeling processes: wild-type DAAM2 cDNA, but not cDNA representing missense variants found in individuals with NS, rescued reduced podocyte migration rate (PMR) and restored reduced filopodia formation in shRNA-induced DAAM2-knockdown podocytes. Filopodia restoration was also induced by the formin-activating molecule IMM-01. DAAM2 also co-localizes and co-immunoprecipitates with INF2, which is intriguing since variants in both formins cause NS. Using in~vitro bulk and TIRF microscopy assays, we find that DAAM2 variants alter actin assembly activities of the formin. In a Xenopus daam2-CRISPR knockout model, we demonstrate actin dysregulation in~vivo and glomerular maldevelopment that is rescued by WT-DAAM2 mRNA. We conclude that DAAM2 variants are a likely cause of monogenic human SRNS due to actin dysregulation in podocytes. Further, we provide evidence that DAAM2-associated SRNS may be amenable to treatment using actin regulating compounds.

}, keywords = {Actins, Alleles, Animals, Animals, Genetically Modified, Cell Movement, Cytoplasm, Formins, Genetic Variation, Humans, Kidney, Kidney Glomerulus, Microfilament Proteins, Mutation, Missense, Nephrotic Syndrome, Podocytes, Pseudopodia, rho GTP-Binding Proteins, RNA, Small Interfering, Whole Exome Sequencing, Xenopus}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.11.008}, author = {Schneider, Ronen and Deutsch, Konstantin and Hoeprich, Gregory J and Marquez, Jonathan and Hermle, Tobias and Braun, Daniela A and Seltzsam, Steve and Kitzler, Thomas M and Mao, Youying and Buerger, Florian and Majmundar, Amar J and Onuchic-Whitford, Ana C and Kolvenbach, Caroline M and Schierbaum, Luca and Schneider, Sophia and Halawi, Abdul A and Nakayama, Makiko and Mann, Nina and Connaughton, Dervla M and Kl{\"a}mbt, Verena and Wagner, Matias and Riedhammer, Korbinian M and Renders, Lutz and Katsura, Yoshichika and Thumkeo, Dean and Soliman, Neveen A and Mane, Shrikant and Lifton, Richard P and Shril, Shirlee and Khokha, Mustafa K and Hoefele, Julia and Goode, Bruce L and Hildebrandt, Friedhelm} } @article {615, title = {Mutation in the intracellular chloride channel CLCC1 associated with autosomal recessive retinitis pigmentosa.}, journal = {PLoS Genet}, volume = {14}, year = {2018}, month = {2018 08}, pages = {e1007504}, abstract = {

We identified a homozygous missense alteration (c.75C>A, p.D25E) in CLCC1, encoding a presumptive intracellular chloride channel highly expressed in the retina, associated with autosomal recessive retinitis pigmentosa (arRP) in eight consanguineous families of Pakistani descent. The p.D25E alteration decreased CLCC1 channel function accompanied by accumulation of mutant protein in granules within the ER lumen, while siRNA knockdown of CLCC1 mRNA induced apoptosis in cultured ARPE-19 cells. TALEN KO in zebrafish was lethal 11 days post fertilization. The depressed electroretinogram (ERG) cone response and cone spectral sensitivity of 5 dpf KO zebrafish and reduced eye size, retinal thickness, and expression of rod and cone opsins could be rescued by injection of wild type CLCC1 mRNA. Clcc1+/- KO mice showed decreased ERGs and photoreceptor number. Together these results strongly suggest that intracellular chloride transport by CLCC1 is a critical process in maintaining retinal integrity, and CLCC1 is crucial for survival and function of retinal cells.

}, keywords = {Animals, Asian Continental Ancestry Group, Cell Line, Chloride Channels, Cytoplasm, Eye Proteins, HEK293 Cells, Homozygote, Humans, Mice, Mice, Knockout, Mutation, Missense, Pakistan, Retina, Retinal Cone Photoreceptor Cells, Retinal Rod Photoreceptor Cells, Retinitis Pigmentosa, Zebrafish}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007504}, author = {Li, Lin and Jiao, Xiaodong and D{\textquoteright}Atri, Ilaria and Ono, Fumihito and Nelson, Ralph and Chan, Chi-Chao and Nakaya, Naoki and Ma, Zhiwei and Ma, Yan and Cai, Xiaoying and Zhang, Longhua and Lin, Siying and Hameed, Abdul and Chioza, Barry A and Hardy, Holly and Arno, Gavin and Hull, Sarah and Khan, Muhammad Imran and Fasham, James and Harlalka, Gaurav V and Michaelides, Michel and Moore, Anthony T and Coban Akdemir, Zeynep Hande and Jhangiani, Shalini and Lupski, James R and Cremers, Frans P M and Qamar, Raheel and Salman, Ahmed and Chilton, John and Self, Jay and Ayyagari, Radha and Kabir, Firoz and Naeem, Muhammad Asif and Ali, Muhammad and Akram, Javed and Sieving, Paul A and Riazuddin, Sheikh and Baple, Emma L and Riazuddin, S Amer and Crosby, Andrew H and Hejtmancik, J Fielding} } @article {455, title = {Variants in the Oxidoreductase PYROXD1 Cause Early-Onset Myopathy with Internalized Nuclei and Myofibrillar Disorganization.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Nov 03}, pages = {1086-1105}, abstract = {

This study establishes PYROXD1 variants as a cause of early-onset myopathy and uses biospecimens and cell lines, yeast, and zebrafish models to elucidate the fundamental role of PYROXD1 in skeletal muscle. Exome sequencing identified recessive variants in PYROXD1 in nine probands from five families. Affected individuals presented in infancy or childhood with slowly progressive proximal and distal weakness, facial weakness, nasal speech, swallowing difficulties, and normal to moderately elevated creatine kinase. Distinctive histopathology showed abundant internalized nuclei, myofibrillar disorganization, desmin-positive inclusions, and thickened Z-bands. PYROXD1 is a nuclear-cytoplasmic pyridine nucleotide-disulphide reductase (PNDR). PNDRs are flavoproteins (FAD-binding) and catalyze pyridine-nucleotide-dependent (NAD/NADH) reduction of thiol residues in other proteins. Complementation experiments in yeast lacking glutathione reductase glr1 show that human PYROXD1 has reductase activity that is strongly impaired by the disease-associated missense mutations. Immunolocalization studies in human muscle and zebrafish myofibers demonstrate that PYROXD1 localizes to the nucleus and to striated sarcomeric compartments. Zebrafish with ryroxD1 knock-down recapitulate features of PYROXD1 myopathy with sarcomeric disorganization, myofibrillar aggregates, and marked swimming defect. We characterize variants in the oxidoreductase PYROXD1 as a cause of early-onset myopathy with distinctive histopathology and introduce altered redox regulation as a primary cause of congenital muscle disease.

}, keywords = {Amino Acid Sequence, Animals, Cell Nucleus, Cercopithecus aethiops, Cohort Studies, COS Cells, Creatine Kinase, Cytoplasm, Distal Myopathies, ELAV-Like Protein 4, Female, Flavoproteins, Gene Deletion, Genetic Variation, Genome-Wide Association Study, Glutathione Reductase, HEK293 Cells, Humans, Male, Muscle, Skeletal, Mutation, Missense, Myopathies, Structural, Congenital, Oxidoreductases, Pedigree, Protein Conformation, Saccharomyces cerevisiae Proteins, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.09.005}, author = {O{\textquoteright}Grady, Gina L and Best, Heather A and Sztal, Tamar E and Schartner, Vanessa and Sanjuan-Vazquez, Myriam and Donkervoort, Sandra and Abath Neto, Osorio and Sutton, Roger Bryan and Ilkovski, Biljana and Romero, Norma Beatriz and Stojkovic, Tanya and Dastgir, Jahannaz and Waddell, Leigh B and Boland, Anne and Hu, Ying and Williams, Caitlin and Ruparelia, Avnika A and Maisonobe, Thierry and Peduto, Anthony J and Reddel, Stephen W and Lek, Monkol and Tukiainen, Taru and Cummings, Beryl B and Joshi, Himanshu and Nectoux, Juliette and Brammah, Susan and Deleuze, Jean-Fran{\c c}ois and Ing, Viola Oorschot and Ramm, Georg and Ardicli, Didem and Nowak, Kristen J and Talim, Beril and Topaloglu, Haluk and Laing, Nigel G and North, Kathryn N and MacArthur, Daniel G and Friant, Sylvie and Clarke, Nigel F and Bryson-Richardson, Robert J and B{\"o}nnemann, Carsten G and Laporte, Jocelyn and Cooper, Sandra T} } @article {267, title = {Adenylate cyclase 1 (ADCY1) mutations cause recessive hearing impairment in humans and defects in hair cell function and hearing in zebrafish.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Jun 15}, pages = {3289-98}, abstract = {

Cyclic AMP (cAMP) production, which is important for mechanotransduction within the inner ear, is catalyzed by adenylate cyclases (AC). However, knowledge of the role of ACs in hearing is limited. Previously, a novel autosomal recessive non-syndromic hearing impairment locus DFNB44 was mapped to chromosome 7p14.1-q11.22 in a consanguineous family from Pakistan. Through whole-exome sequencing of DNA samples from hearing-impaired family members, a nonsense mutation c.3112C>T (p.Arg1038*) within adenylate cyclase 1 (ADCY1) was identified. This stop-gained mutation segregated with hearing impairment within the family and was not identified in ethnically matched controls or within variant databases. This mutation is predicted to cause the loss of 82 amino acids from the carboxyl tail, including highly conserved residues within the catalytic domain, plus a calmodulin-stimulation defect, both of which are expected to decrease enzymatic efficiency. Individuals who are homozygous for this mutation had symmetric, mild-to-moderate mixed hearing impairment. Zebrafish adcy1b morphants had no FM1-43 dye uptake and lacked startle response, indicating hair cell dysfunction and gross hearing impairment. In the mouse, Adcy1 expression was observed throughout inner ear development and maturation. ADCY1 was localized to the cytoplasm of supporting cells and hair cells of the cochlea and vestibule and also to cochlear hair cell nuclei and stereocilia. Ex vivo studies in COS-7 cells suggest that the carboxyl tail of ADCY1 is essential for localization to actin-based microvilli. These results demonstrate that ADCY1 has an evolutionarily conserved role in hearing and that cAMP signaling is important to hair cell function within the inner ear.

}, keywords = {Adenylyl Cyclases, Animals, Cercopithecus aethiops, Codon, Nonsense, COS Cells, Cyclic AMP, Cytoplasm, Ear, Inner, Female, Hair Cells, Auditory, Hearing Loss, Humans, Labyrinth Supporting Cells, Male, Mice, Zebrafish}, issn = {1460-2083}, doi = {10.1093/hmg/ddu042}, author = {Santos-Cortez, Regie Lyn P and Lee, Kwanghyuk and Giese, Arnaud P and Ansar, Muhammad and Amin-ud-Din, Muhammad and Rehn, Kira and Wang, Xin and Aziz, Abdul and Chiu, Ilene and Hussain Ali, Raja and Smith, Joshua D and Shendure, Jay and Bamshad, Michael and Nickerson, Deborah A and Ahmed, Zubair M and Ahmad, Wasim and Riazuddin, Saima and Leal, Suzanne M} }