scholarly journals Short Stature is Progressive in Patients with Heterozygous NPR2 Mutations

2020 ◽  
Vol 105 (10) ◽  
pp. 3190-3202 ◽  
Author(s):  
Patrick C Hanley ◽  
Harsh S Kanwar ◽  
Corine Martineau ◽  
Michael A Levine
Keyword(s):  
Short Stature ◽  
Mammalian Cells ◽  
Extended Family ◽  
Medical Center ◽  
Academic Medical Center ◽  
Dominant Negative ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Wild Type ◽  
Z Scores

Abstract Background NPR2 encodes atrial natriuretic peptide receptor B (ANPRB), a regulator of skeletal growth. Biallelic loss-of-function mutations in NPR2 result in acromesomelic dysplasia Maroteaux type (AMDM; OMIM 602875), while heterozygous mutations may account for 2% to 6% of idiopathic short stature (ISS). Objective Describe the physical proportions and growth characteristics of an extended family with novel NPR2 mutations including members with AMDM, ISS, or normal stature. Design and Participants We performed whole exome sequencing in 2 healthy parents and 2 children with AMDM. Detailed genotyping and phenotyping were performed on members of a multigenerational family in an academic medical center. We expressed mutant proteins in mammalian cells and characterized expression and function. Results The sisters with AMDM were compound heterozygotes for missense mutations in the NPR2 gene, a novel p.P93S (maternal) and the previously reported p.R989L (paternal). Both mutant ANPRB proteins were normally expressed in HEK293T cells and exhibited dominant negative effects on wild-type ANPRB catalytic activity. Heterozygous relatives had proportionate short stature (height z-scores −2.06 ± 0.97, median ± SD) compared with their wild-type siblings (−1.37 ± 0.59). Height z-scores progressively and significantly decreased as NPR2-heterozygous children matured, while remaining constant in their wild-type siblings. Conclusions Biallelic NPR2 mutations cause severe skeletal dysplasia (AMDM), whereas heterozygous mutations lead to a subtler phenotype characterized by progressive short stature with by increasing loss of height potential with age.

scholarly journals Mutation-specific non-canonical pathway of PTEN as a distinct therapeutic target for glioblastoma

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Seung Won Choi ◽  
Yeri Lee ◽  
Kayoung Shin ◽  
Harim Koo ◽  
Donggeon Kim ◽  
...  
Keyword(s):  
Functional Properties ◽  
Therapeutic Target ◽  
Medical Center ◽  
Dominant Negative ◽  
The Cancer Genome Atlas ◽  
Dominant Negative Effect ◽  
Cell Periphery ◽  
Missense Mutations ◽  
Phosphatase Domain ◽  
Mutant Proteins

AbstractPTEN is one of the most frequently altered tumor suppressor genes in malignant tumors. The dominant-negative effect of PTEN alteration suggests that the aberrant function of PTEN mutation might be more disastrous than deletion, the most frequent genomic event in glioblastoma (GBM). This study aimed to understand the functional properties of various PTEN missense mutations and to investigate their clinical relevance. The genomic landscape of PTEN alteration was analyzed using the Samsung Medical Center GBM cohort and validated via The Cancer Genome Atlas dataset. Several hotspot mutations were identified, and their subcellular distributions and phenotypes were evaluated. We established a library of cancer cell lines that overexpress these mutant proteins using the U87MG and patient-derived cell models lacking functional PTEN. PTEN mutations were categorized into two major subsets: missense mutations in the phosphatase domain and truncal mutations in the C2 domain. We determined the subcellular compartmentalization of four mutant proteins (H93Y, C124S, R130Q, and R173C) from the former group and found that they had distinct localizations; those associated with invasive phenotypes (‘edge mutations’) localized to the cell periphery, while the R173C mutant localized to the nucleus. Invasive phenotypes derived from edge substitutions were unaffected by an anti-PI3K/Akt agent but were disrupted by microtubule inhibitors. PTEN mutations exhibit distinct functional properties regarding their subcellular localization. Further, some missense mutations (‘edge mutations’) in the phosphatase domain caused enhanced invasiveness associated with dysfunctional cytoskeletal assembly, thus suggesting it to be a potent therapeutic target.

scholarly journals RSR1, a ras-like gene homologous to Krev-1 (smg21A/rap1A): role in the development of cell polarity and interactions with the Ras pathway in Saccharomyces cerevisiae.

1992 ◽  
Vol 12 (2) ◽  
pp. 758-766 ◽  
Author(s):  
R Ruggieri ◽  
A Bender ◽  
Y Matsui ◽  
S Powers ◽  
Y Takai ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Polarity ◽  
Copy Number ◽  
Mammalian Cells ◽  
Direct Interaction ◽  
Dominant Negative ◽  
Yeast Cells ◽  
Wild Type ◽  
Ras Gene ◽  
Ras Pathway

The Saccharomyces cerevisiae ras-like gene RSR1 is particularly closely related to the mammalian gene Krev-1 (also known as smg21A and rap1A). RSR1 was originally isolated as a multicopy suppressor of a cdc24 mutation, which causes an inability to bud or establish cell polarity. Deletion of RSR1 itself does not affect growth but causes a randomization of bud position. We have now constructed mutant alleles of RSR1 encoding proteins with substitutions of Val for Gly at position 12 (analogous to constitutively activated Ras proteins) or Asn for Lys at position 16 (analogous to a dominant-negative Ras protein). rsr1Val-12 could not restore a normal budding pattern to an rsr1 deletion strain but could suppress a cdc24 mutation when overexpressed. rsr1Asn-16 could randomize the budding pattern of a wild-type strain even in low copy number but was not lethal even in high copy number. These and other results suggest that Rsr1p functions only in bud site selection and not in subsequent events of polarity establishment and bud formation, that this function involves a cycling between GTP-bound and GDP-bound forms of the protein, and that the suppression of cdc24 involves direct interaction between Rsr1p[GTP] and Cdc24p. Functional homology between Rsr1p and Krev-1 p21 was suggested by the observations that expression of the latter protein in yeast cells could both suppress a cdc24 mutation and randomize the budding pattern of wild-type cells. As Krev-1 overexpression can suppress ras-induced transformation of mammalian cells, we looked for effects of RSR1 on the S. cerevisiae Ras pathway. Although no suppression of the activated RAS2Val-19 allele was observed, overexpression of rsr1Val-12 suppressed the lethality of strains lacking RAS gene function, apparently through a direct activation of adenyl cyclase. This interaction of Rsr1p with the effector of Ras in S. cerevisiae suggests that Krev-1 may revert ras-induced transformation of mammalian cells by affecting the interaction of ras p21 with its effector.

Revisiting Li-Fraumeni Syndrome From TP53 Mutation Carriers

2015 ◽  
Vol 33 (21) ◽  
pp. 2345-2352 ◽  
Author(s):  
Gaëlle Bougeard ◽  
Mariette Renaux-Petel ◽  
Jean-Michel Flaman ◽  
Camille Charbonnier ◽  
Pierre Fermey ◽  
...  
Keyword(s):  
Tp53 Mutation ◽  
Soft Tissue Sarcomas ◽  
Dominant Negative ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Li Fraumeni Syndrome ◽  
Tumor Onset ◽  
Mutation Carriers ◽  
The Mean ◽  
Li Fraumeni

Purpose The aim of the study was to update the description of Li-Fraumeni syndrome (LFS), a remarkable cancer predisposition characterized by extensive clinical heterogeneity. Patients and Methods From 1,730 French patients suggestive of LFS, we identified 415 mutation carriers in 214 families harboring 133 distinct TP53 alterations and updated their clinical presentation. Results The 322 affected carriers developed 552 tumors, and 43% had developed multiple malignancies. The mean age of first tumor onset was 24.9 years, 41% having developed a tumor by age 18. In childhood, the LFS tumor spectrum was characterized by osteosarcomas, adrenocortical carcinomas (ACC), CNS tumors, and soft tissue sarcomas (STS) observed in 30%, 27%, 26%, and 23% of the patients, respectively. In adults, the tumor distribution was characterized by the predominance of breast carcinomas observed in 79% of the females, and STS observed in 27% of the patients. The TP53 mutation detection rate in children presenting with ACC or choroid plexus carcinomas, and in females with breast cancer before age 31 years, without additional features indicative of LFS, was 45%, 42% and 6%, respectively. The mean age of tumor onset was statistically different (P < .05) between carriers harboring dominant-negative missense mutations (21.3 years) and those with all types of loss of function mutations (28.5 years) or genomic rearrangements (35.8 years). Affected children, except those with ACC, harbored mostly dominant-negative missense mutations. Conclusion The clinical gradient of the germline TP53 mutations, which should be validated by other studies, suggests that it might be appropriate to stratify the clinical management of LFS according to the class of the mutation.

scholarly journals Primary Brain Calcification Causal PiT2 Transport-Knockout Variants can Exert Dominant Negative Effects on Wild-Type PiT2 Transport Function in Mammalian Cells

2016 ◽  
Vol 61 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Frederik Tibert Larsen ◽  
Nina Jensen ◽  
Jacob Kwasi Autzen ◽  
Iben Boutrup Kongsfelt ◽  
Lene Pedersen
Keyword(s):  
Mammalian Cells ◽  
Dominant Negative ◽  
Transport Function ◽  
Wild Type ◽  
Negative Effects ◽  
Brain Calcification

scholarly journals The flatiron mutation in mouse ferroportin acts as a dominant negative to cause ferroportin disease

Blood ◽  
2007 ◽  
Vol 109 (10) ◽  
pp. 4174-4180 ◽  
Author(s):  
Irene E. Zohn ◽  
Ivana De Domenico ◽  
Andrew Pollock ◽  
Diane McVey Ward ◽  
Jessica F. Goodman ◽  
...  
Keyword(s):  
Mouse Model ◽  
Cell Surface ◽  
Kupffer Cells ◽  
Transferrin Saturation ◽  
High Serum ◽  
Dominant Negative ◽  
Iron Loading ◽  
Missense Mutations ◽  
Wild Type ◽  
Export Activity

Abstract Ferroportin disease is caused by mutation of one allele of the iron exporter ferroportin (Fpn/IREG1/Slc40a1/MTP1). All reported human mutations are missense mutations and heterozygous null mutations in mouse Fpn do not recapitulate the human disease. Here we describe the flatiron (ffe) mouse with a missense mutation (H32R) in Fpn that affects its localization and iron export activity. Similar to human patients with classic ferroportin disease, heterozygous ffe/+ mice present with iron loading of Kupffer cells, high serum ferritin, and low transferrin saturation. In macrophages isolated from ffe/+ heterozygous mice and through the use of Fpn plasmids with the ffe mutation, we show that Fpnffe acts as a dominant negative, preventing wild-type Fpn from localizing on the cell surface and transporting iron. These results demonstrate that mutations in Fpn resulting in protein mislocalization act in a dominant-negative fashion to cause disease, and the Fpnffe mouse represents the first mouse model of ferroportin disease.

scholarly journals A Novel Multi-Exon Deletion of PACS1 in a Three-Generation Pedigree: Supplements to PACS1 Neurodevelopmental Disorder Spectrum

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuan Liu ◽  
Hongke Ding ◽  
Tizhen Yan ◽  
Ling Liu ◽  
Lihua Yu ◽  
...  
Keyword(s):  
Neurodevelopmental Disorder ◽  
Dominant Negative ◽  
Facial Features ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Pathogenic Variants ◽  
Cognitive Delay ◽  
Whole Exome ◽  
Before And After ◽  
Exon Deletion

PACS1 neurodevelopmental disorder (PACS1-NDD) is a category of rare disorder characterized by intellectual disability, speech delay, dysmorphic facial features, and developmental delay. Other various physical abnormalities of PACS1-NDD might involve all organs and systems. Notably, there were only two unique missense mutations [c.607C &gt; T (p.Arg203Trp) and c.608G &gt; A (p.Arg203Gln)] in PACS1 that had been identified as pathogenic variants for PACS1-NDD or Schuurs-Hoeijmakers syndrome (SHMS). Previous reports suggested that these common missense variants were likely to act through dominant-negative or gain-of-function effects manner. It is still uncertain whether the intragenic deletion or duplication in PACS1 will be disease-causing. By using whole-exome sequencing, we first identified a novel heterozygous multi-exon deletion covering exons 12–24 in PACS1 (NM_018026) in four individuals (two brothers and their father and grandfather) in a three-generation family. The younger brother was referred to our center prenatally and was evaluated before and after the birth. Unlike SHMS, no typical dysmorphic facial features, intellectual problems, and structural brain anomalies were observed among these four individuals. The brothers showed a mild hypermyotonia of their extremities at the age of 3 months old and recovered over time. Mild speech and cognitive delay were also noticed in the two brothers at the age of 13 and 27 months old, respectively. However, their father and grandfather showed normal language and cognitive competence. This study might supplement the spectrum of PACS1-NDD and demonstrates that the loss of function variation in PACS1 displays no contributions to the typical SHMS which is caused by the recurrent c.607C &gt; T (p.Arg203Trp) variant.

scholarly journals Loss-of-Function Piezo1 Mutations Display Altered Stability Driven by Ubiquitination and Proteasomal Degradation

2021 ◽  
Vol 12 ◽  
Author(s):  
Zijing Zhou ◽  
Jinyuan Vero Li ◽  
Boris Martinac ◽  
Charles D. Cox
Keyword(s):  
Membrane Trafficking ◽  
Proteasome Inhibition ◽  
Proteasomal Degradation ◽  
Missense Mutations ◽  
Turnover Rates ◽  
Loss Of Function ◽  
Wild Type ◽  
Mutant Proteins ◽  
Lymphatic Dysplasia ◽  
Therapeutic Avenue

Missense mutations in the gene that encodes for the mechanically-gated ion channel Piezo1 have been linked to a number of diseases. Gain-of-function variants are linked to a hereditary anaemia and loss-of-function variants have been linked to generalized lymphatic dysplasia and bicuspid aortic valve. Two previously characterized mutations, S217L and G2029R, both exhibit reduced plasma membrane trafficking. Here we show that both mutations also display reduced stability and higher turnover rates than wild-type Piezo1 channels. This occurs through increased ubiquitination and subsequent proteasomal degradation. Congruent with this, proteasome inhibition using N-acetyl-l-leucyl-l-leucyl-l-norleucinal (ALLN) reduced the degradation of both mutant proteins. While ALLN treatment could not rescue the function of S217L we show via multiple complementary methodologies that proteasome inhibition via ALLN treatment can not only prevent G2029R turnover but increase the membrane localized pool of this variant and the functional Piezo1 mechanosensitive currents. This data in combination with a precision medicine approach provides a new potential therapeutic avenue for the treatment of Piezo1 mediated channelopathies.

scholarly journals Germline Variants of RUNX-1 in Myeloid Malignancy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3926-3926
Author(s):  
Alek d Nielsen ◽  
Sayer Alharbi ◽  
Cassandra M. Hirsch ◽  
Bartlomiej P Przychodzen ◽  
Mikkael A. Sekeres ◽  
...  
Keyword(s):  
Amino Acid ◽  
Board Of Directors ◽  
Dominant Negative ◽  
Missense Mutations ◽  
Wild Type ◽  
Runt Domain ◽  
Advisory Committees ◽  
Myeloid Malignancy ◽  
Myeloid Neoplasms ◽  
Platelet Disorder

Abstract Mutation of the master transcription factor RUNX1 (NM_001754) has a well characterized role in the pathogenesis of myeloid neoplasms. RUNX1 is located at 21q22 and is composed of a c-terminal transactivation domain (TAD) (269-480) and an n-terminal RUNT domain (amino acid 76-209) that binds DNA and mediates heterodimerization with CBF-β. If the RUNT domain is disrupted a RUNX1 mutant will behave in a dominant negative fashion. Mutations leaving the RUNT domain intact result in haploinsufficiency compounded by CBF-β binding site competition with the wild-type allele. Germline (GL) RUNX1 mutations cause the autosomal dominant predisposition syndrome familial platelet disorder with propensity to myeloid malignancy (FPDMM). In FPDMM, RUNX1 mutations, including RUNT domain missense mutations or nonsense mutations throughout the gene, confer mild chronic platelet disorders and a lifetime risk of MDS/AML. As with other GL predisposition syndromes a secondary event is considered necessary for progression, typically an additional mutation in the wild type RUNX1 allele. Onset of MDS/AML occurs at a median age of 33 years but the latency can be variable and ease of detection in younger cases likely distorts summary statistics. Inherited mutations in adults may be difficult to distinguish and have not been systematically explored. We hypothesize that a fraction of patients with otherwise typical RUNX1-positive MDS or related disorders are in fact carriers of a RUNX1 GL mutation. DNA obtained from a cohort of 1451 patients with myeloid neoplasia was analyzed using a multiamplicon deep next-generation sequencing (NGS) panel including all ORFs of RUNX1. A total of 124 patients (8.5%) were found to carry 117 unique RUNX1 mutations. Of these, 59 hits were missense and 58 nonsense; and in 94 (76%) of cases the RUNT domain was disrupted. Eighteen (15.3% RUNX1 positive patients) were previously described in FPDMM. We applied various bio analytic criteria to designate somatic status in 57 patients. The remaining 64 RUNX1 mutations were further investigated, when possible, by paired capillary sequencing of CD3- mononuclear DNA and in-vitro expanded CD3+ T-Cell DNA. We found 5/31 (16%) of these cases carried mutation in both myeloid and lymphoid lineages and were designated GL. This included 2 post-RUNT truncations (p.Y281*, p.S410*) and two RUNT domain missense mutations (p.R80C, p.S141L) all of which are expected to produce a dominant negative phenotype. A 5th GL mutation of uncertain significance in the TAD (p.M310I) was also discovered. Excluding this TAD missense mutation, each of these have been described as somatic factors in myeloid disease. The truncation at amino acid 410 is further downstream than all reported FPDMM variants to date. Chart review revealed an anamnestic presence of thrombocytopenia in 80% of proposed FPD patients. Suggestive family history was found in both truncated cases, with hematologic malignancy presenting in a 1st degree relative before 30 years of age. Median age at diagnosis of MDS/AML in GL cases was 46 years (range: 18-68 years) compared to 65 years in the cases designated somatic (range: 37-87 years). Two cases (p.S410* and p.M310I) had cytogenetic abnormalities on the 21st chromosome (trisomy 21 and t(8;21) respectively) and had no other molecular abnormalities detected by our NGS panel. A mutation in GPR98 of unknown significance was found with p.Y281*. Lastly the p.S141L mutant had cooperating mutations in chromatin modifiers ASXL1 and BCOR, and in RNA splicing gene LUC7L2. This study of an exemplary GL leukemia gene suggests that systematic searches for known and potential GL predisposition genes in otherwise typical adult cohorts may reveal a GL role in the evolution of myeloid neoplasms. Future work to determine genetic predisposition to leukemia in adults is essential. Disclosures Sekeres: Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees. Carraway:Celgene: Research Funding, Speakers Bureau; Baxalta: Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Characterization of Leu777Pro and Ile865Thr type IIA von Willebrand disease mutations

Blood ◽  
1994 ◽  
Vol 83 (6) ◽  
pp. 1551-1557 ◽  
Author(s):  
SE Lyons ◽  
KA Cooney ◽  
P Bockenstedt ◽  
D Ginsburg
Keyword(s):  
Molecular Weight ◽  
Mammalian Cells ◽  
Intracellular Transport ◽  
Von Willebrand Disease ◽  
Normal Donor ◽  
Missense Mutations ◽  
Wild Type ◽  
Full Spectrum ◽  
Group I ◽  
Von Willebrand

Abstract Type IIA von Willebrand disease (vWD) is an autosomal dominant bleeding disorder characterized by a qualitative defect in von Willebrand factor (vWF). A number of missense mutations responsible for type IIA vWD have recently been identified. This report examines the type IIA vWD mutations Leu777-->Pro and Ile865-->Thr by expression of recombinant vWF containing mutant and wild-type (WT) sequences. Recombinant vWF containing the L777P mutation (vWFL777P) showed markedly impaired secretion compared with that for wild-type vWF (vWFWT) after DNA transfection into mammalian cells. Multimer analysis of secreted vWFL777P showed predominantly low molecular weight forms. In contrast, recombinant vWF containing the I865T mutation (vWFI865T) was processed in a pattern similar to vWFWT, with secretion of the full spectrum of vWF multimers. Thus, L777P and I865T are subclassified as type IIA group I and group II mutations, respectively. Analysis of platelet vWF from a patient heterozygous for the L777P mutation shows reduced large vWF multimers in a pattern similar to plasma, consistent with the intracellular transport defect predicted for a group I mutation. An increase in the proportion of high molecular weight multimers observed in type IIA vWD patient plasma, after renal transplantation from a normal donor, suggests that the kidney endothelium may be a major source of plasma vWF.

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