Genotype-Phenotype Comparison in POGZ-Related Neurodevelopmental Disorders by Using Clinical Scoring

POGZ-related disorders (also known as White-Sutton syndrome) encompass a wide range of neurocognitive abnormalities and other accompanying anomalies. Disease severity varies widely among POGZ patients and studies investigating genotype-phenotype association are scarce. Therefore, our aim was to collect data on previously unreported POGZ patients and perform a large-scale phenotype-genotype comparison from published data. Overall, 117 POGZ patients′ genotype and phenotype data were included in the analysis, including 12 novel patients. A severity scoring system was developed for the comparison. Mild and severe phenotypes were compared with the types and location of the variants and the predicted presence or absence of nonsense-mediated RNA decay (NMD). Missense variants were more often associated with mild phenotypes (p = 0.0421) and truncating variants predicted to escape NMD presented with more severe phenotypes (p < 0.0001). Within this group, variants in the prolin-rich region of the POGZ protein were associated with the most severe phenotypes (p = 0.0004). Our study suggests that gain-of-function or dominant negative effect through escaping NMD and the location of the variants in the prolin-rich domain of the protein may play an important role in the severity of manifestations of POGZ–associated neurodevelopmental disorders.

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Regulated Disruption of Inositol 1,4,5-Trisphosphate Signaling in Caenorhabditis elegans Reveals New Functions in Feeding and Embryogenesis

Molecular Biology of the Cell ◽

10.1091/mbc.01-08-0422 ◽

2002 ◽

Vol 13 (4) ◽

pp. 1329-1337 ◽

Cited By ~ 52

Author(s):

Denise S. Walker ◽

Nicholas J.D. Gower ◽

Sung Ly ◽

Gemma L. Bradley ◽

Howard A. Baylis

Keyword(s):

Binding Domain ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Animal Cells ◽

Specific Expression ◽

C Elegans ◽

Wide Range ◽

Inositol 1,4,5 Trisphosphate ◽

Negative Effect ◽

Pharyngeal Pumping

Inositol 1,4,5-trisphosphate (IP3) is an important second messenger in animal cells and is central to a wide range of cellular responses. The major intracellular activity of IP3 is to regulate release of Ca2+ from intracellular stores through IP3 receptors (IP3Rs). We describe a system for the transient disruption of IP3 signaling in the model organismCaenorhabditis elegans. The IP3 binding domain of the C. elegans IP3R, ITR-1, was expressed from heat shock-induced promoters in live animals. This results in a dominant-negative effect caused by the overexpressed IP3 binding domain acting as an IP3“sponge.” Disruption of IP3 signaling resulted in disrupted defecation, a phenotype predicted by previous genetic studies. This approach also identified two new IP3-mediated processes. First, the up-regulation of pharyngeal pumping in response to food is dependent on IP3 signaling. RNA-mediated interference studies and analysis of itr-1mutants show that this process is also IP3R dependent. Second, the tissue-specific expression of the dominant-negative construct enabled us to circumvent the sterility associated with loss of IP3 signaling through the IP3R and thus determine that IP3-mediated signaling is required for multiple steps in embryogenesis, including cytokinesis and gastrulation.

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NKCC1: Newly Found as a Human Disease-Causing Ion Transporter

Function ◽

10.1093/function/zqaa028 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Rainelli Koumangoye ◽

Lisa Bastarache ◽

Eric Delpire

Keyword(s):

De Novo ◽

Stop Codon ◽

Neurodevelopmental Disorder ◽

Premature Stop Codon ◽

Dominant Negative ◽

De Novo Mutation ◽

Dominant Negative Effect ◽

Salt Wasting ◽

Wide Range ◽

Negative Effect

Abstract Among the electroneutral Na+-dependent chloride transporters, NKCC1 had until now evaded identification as a protein causing human diseases. The closely related SLC12A transporters, NKCC2 and NCC have been identified some 25 years ago as responsible for Bartter and Gitelman syndromes: two renal-dependent salt wasting disorders. Absence of disease was most surprising since the NKCC1 knockout mouse was shown in 1999 to be viable, albeit with a wide range of deleterious phenotypes. Here we summarize the work of the past 5 years that introduced us to clinical cases involving NKCC1. The most striking cases are of 3 children with inherited mutations, who have complete absence of NKCC1 expression. These cases establish that lack of NKCC1 causes deafness; CFTR-like secretory defects with mucus accumulation in lung and intestine; severe xerostomia, hypotonia, dysmorphic facial features, and severe neurodevelopmental disorder. Another intriguing case is of a patient with a dominant deleterious SLC12A2 allele. This de novo mutation introduced a premature stop codon leading to a truncated protein. This mutant transporter seems to exert dominant-negative effect on wild-type transporter only in epithelial cells. The patient who suffers from lung, bladder, intestine, pancreas, and multiple endocrine abnormalities has, however, normal hearing and cognition. Finally, new reports substantiate the haploinsufficiency prediction of the SLC12A2 gene. Cases with single allele mutations in SLC12A2 have been linked to hearing loss and neurodevelopmental disorders.

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A Dominant Negative Effect of eth-1r, a Mutant Allele of the Neurospora crassa S-Adenosylmethionine Synthetase-Encoding Gene Conferring Resistance to the Methionine Toxic Analogue Ethionine

Genetics ◽

10.1093/genetics/144.4.1455 ◽

1996 ◽

Vol 144 (4) ◽

pp. 1455-1462

Author(s):

José L Barra ◽

Mario R Mautino ◽

Alberto L Rosa

Keyword(s):

Neurospora Crassa ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Resistant Phenotype ◽

Negative Effect ◽

Encoding Gene ◽

Adenosylmethionine Synthetase ◽

Adomet Synthetase ◽

Identical Gene

eth-1r a thermosensitive allele of the Neurospora crassa S-adenosylmethionine (AdoMet) synthetase gene that confers ethionine resistance, has been cloned and sequenced. Replacement of an aspartic amino acid residue (D48 → N48), perfectly conserved in prokaryotic, fungal and higher eukaryotic AdoMet synthetases, was found responsible for both thermosensitivity and ethionine resistance conferred by eth-1r. Gene fusion constructs, designed to overexpress eth-1r in vivo, render transformant cells resistant to ethionine. Dominance of ethionine resistance was further demonstrated in eth-1 +/eth-1r partial diploids carrying identical gene doses of both alleles. Heterozygous eth-1 +/eth-1r cells have, at the same time, both the thermotolerance conferred by eth-1 + and the ethionine-resistant phenotype conferred by eth-1r. AdoMet levels and AdoMet synthetase activities were dramatically decreased in heterozygous eth-1 +/eth-1r cells. We propose that this negative effect exerted by eth-1r results from the in vivo formation of heteromeric eth-1 +/eth-1r AdoMet synthetase molecules.

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Evidence for a dominant‐negative effect of a missense mutation in the SERPING1 gene responsible for hereditary angioedema type I

The Journal of Dermatology ◽

10.1111/1346-8138.15930 ◽

2021 ◽

Author(s):

Shuichiro Yasuno ◽

Osamu Ansai ◽

Ryota Hayashi ◽

Sawako Nakamura ◽

Yutaka Shimomura

Keyword(s):

Missense Mutation ◽

Hereditary Angioedema ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Type I ◽

Negative Effect ◽

Serping1 Gene

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Restoration of Silencing in Saccharomyces cerevisiae by Tethering of a Novel Sir2-Interacting Protein, Esc8

Genetics ◽

10.1093/genetics/162.2.633 ◽

2002 ◽

Vol 162 (2) ◽

pp. 633-645 ◽

Cited By ~ 2

Author(s):

Guido Cuperus ◽

David Shore

Keyword(s):

Protein A ◽

Dominant Negative ◽

Class I ◽

Dominant Negative Effect ◽

Rna Pol Ii ◽

Interacting Protein ◽

Nucleosome Remodeling ◽

Negative Effect ◽

Close Homolog

Abstract We previously described two classes of SIR2 mutations specifically defective in either telomeric/HM silencing (class I) or rDNA silencing (class II) in S. cerevisiae. Here we report the identification of genes whose protein products, when either overexpressed or directly tethered to the locus in question, can establish silencing in SIR2 class I mutants. Elevated dosage of SCS2, previously implicated as a regulator of both inositol biosynthesis and telomeric silencing, suppressed the dominant-negative effect of a SIR2-143 mutation. In a genetic screen for proteins that restore silencing when tethered to a telomere, we isolated ESC2 and an uncharacterized gene, (YOL017w), which we call ESC8. Both Esc2p and Esc8p interact with Sir2p in two-hybrid assays, and the Esc8p-Sir2 interaction is detected in vitro. Interestingly, Esc8p has a single close homolog in yeast, the ISW1-complex factor Ioc3p, and has also been copurified with Isw1p, raising the possibility that Esc8p is a component of an Isw1p-containing nucleosome remodeling complex. Whereas esc2 and esc8 deletion mutants alone have only marginal silencing defects, cells lacking Isw1p show a strong silencing defect at HMR but not at telomeres. Finally, we show that Esc8p interacts with the Gal11 protein, a component of the RNA pol II mediator complex.

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Dominant Negative Mutants Implicate STAT5 in Myeloid Cell Proliferation and Neutrophil Differentiation

Blood ◽

10.1182/blood.v93.12.4154 ◽

1999 ◽

Vol 93 (12) ◽

pp. 4154-4166 ◽

Cited By ~ 80

Author(s):

Robert L. Ilaria ◽

Robert G. Hawley ◽

Richard A. Van Etten

Keyword(s):

Dna Binding ◽

Transcriptional Activation ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Cytokine Signaling ◽

Transactivation Domain ◽

Negative Effects ◽

Murine Bone Marrow ◽

Negative Effect

Abstract STAT5 is a member of the signal transducers and activation of transcription (STAT) family of latent transcription factors activated in a variety of cytokine signaling pathways. We introduced alanine substitution mutations in highly conserved regions of murine STAT5A and studied the mutants for dimerization, DNA binding, transactivation, and dominant negative effects on erythropoietin-induced STAT5-dependent transcriptional activation. The mutations included two near the amino-terminus (W255KR→AAA and R290QQ→AAA), two in the DNA-binding domain (E437E→AA and V466VV→AAA), and a carboxy-terminal truncation of STAT5A (STAT5A/▵53C) analogous to a naturally occurring isoform of rat STAT5B. All of the STAT mutant proteins were tyrosine phosphorylated by JAK2 and heterodimerized with STAT5B except for the WKR mutant, suggesting an important role for this region in STAT5 for stabilizing dimerization. The WKR, EE, and VVV mutants had no detectable DNA-binding activity, and the WKR and VVV mutants, but not EE, were defective in transcriptional induction. The VVV mutant had a moderate dominant negative effect on erythropoietin-induced STAT5 transcriptional activation, which was likely due to the formation of heterodimers that are defective in DNA binding. Interestingly, the WKR mutant had a potent dominant negative effect, comparable to the transactivation domain deletion mutant, ▵53C. Stable expression of either the WKR or ▵53C STAT5 mutants in the murine myeloid cytokine-dependent cell line 32D inhibited both interleukin-3–dependent proliferation and granulocyte colony-stimulating factor (G-CSF)–dependent differentiation, without induction of apoptosis. Expression of these mutants in primary murine bone marrow inhibited G-CSF–dependent granulocyte colony formation in vitro. These results demonstrate that mutations in distinct regions of STAT5 exert dominant negative effects on cytokine signaling, likely through different mechanisms, and suggest a role for STAT5 in proliferation and differentiation of myeloid cells.

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Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies

Antibiotics ◽

10.3390/antibiotics10070830 ◽

2021 ◽

Vol 10 (7) ◽

pp. 830

Author(s):

Prasangi Rajapaksha ◽

Isoiza Ojo ◽

Ling Yang ◽

Ankit Pandeya ◽

Thilini Abeywansha ◽

...

Keyword(s):

Efflux Pump ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Assembly Process ◽

Multidrug Efflux ◽

E Coli ◽

Multidrug Efflux Pumps ◽

Negative Effect ◽

Dynamic Assembly ◽

Pump Assembly

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.

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The Diagnostic Journey of a Patient with Prader–Willi-Like Syndrome and a Unique Homozygous SNURF-SNRPN Variant; Bio-Molecular Analysis and Review of the Literature

Genes ◽

10.3390/genes12060875 ◽

2021 ◽

Vol 12 (6) ◽

pp. 875

Author(s):

Karlijn Pellikaan ◽

Geeske M. van Woerden ◽

Lotte Kleinendorst ◽

Anna G. W. Rosenberg ◽

Bernhard Horsthemke ◽

...

Keyword(s):

Intellectual Disability ◽

Single Nucleotide Polymorphism Array ◽

Genetic Defect ◽

Missense Variant ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Pituitary Hormone ◽

Negative Effect

Prader–Willi syndrome (PWS) is a rare genetic condition characterized by hypotonia, intellectual disability, and hypothalamic dysfunction, causing pituitary hormone deficiencies and hyperphagia, ultimately leading to obesity. PWS is most often caused by the loss of expression of a cluster of genes on chromosome 15q11.2-13. Patients with Prader–Willi-like syndrome (PWLS) display features of the PWS phenotype without a classical PWS genetic defect. We describe a 46-year-old patient with PWLS, including hypotonia, intellectual disability, hyperphagia, and pituitary hormone deficiencies. Routine genetic tests for PWS were normal, but a homozygous missense variant NM_003097.3(SNRPN):c.193C>T, p.(Arg65Trp) was identified. Single nucleotide polymorphism array showed several large regions of homozygosity, caused by high-grade consanguinity between the parents. Our functional analysis, the ‘Pipeline for Rapid in silico, in vivo, in vitro Screening of Mutations’ (PRiSM) screen, showed that overexpression of SNRPN-p.Arg65Trp had a dominant negative effect, strongly suggesting pathogenicity. However, it could not be confirmed that the variant was responsible for the phenotype of the patient. In conclusion, we present a unique homozygous missense variant in SNURF-SNRPN in a patient with PWLS. We describe the diagnostic trajectory of this patient and the possible contributors to her phenotype in light of the current literature on the genotype–phenotype relationship in PWS.

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