Loss-of-function mutation in the X-linked TBX22 promoter disrupts an ETS-1 binding site and leads to cleft palate

2014 ◽  
Vol 134 (2) ◽  
pp. 147-158 ◽  
Author(s):  
Xiazhou Fu ◽  
Yibin Cheng ◽  
Jia Yuan ◽  
Chunhua Huang ◽  
Hanhua Cheng ◽  
...  
Keyword(s):  
Cleft Palate ◽  
Binding Site ◽  
Loss Of Function

scholarly journals Doc2b Ca2+ binding site mutants enhance synaptic release at rest at the expense of sustained synaptic strength

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Quentin Bourgeois-Jaarsma ◽  
Matthijs Verhage ◽  
Alexander J. Groffen
Keyword(s):  
Binding Site ◽  
Neurotransmitter Release ◽  
Action Potentials ◽  
Synaptic Strength ◽  
Cultured Neurons ◽  
Loss Of Function ◽  
Short Term ◽  
Synaptic Release ◽  
Activated State ◽  
Primary Cultured Neurons

Abstract Communication between neurons involves presynaptic neurotransmitter release which can be evoked by action potentials or occur spontaneously as a result of stochastic vesicle fusion. The Ca2+-binding double C2 proteins Doc2a and –b were implicated in spontaneous and asynchronous evoked release, but the mechanism remains unclear. Here, we compared wildtype Doc2b with two Ca2+ binding site mutants named DN and 6A, previously classified as gain- and loss-of-function mutants. They carry the substitutions D218,220N or D163,218,220,303,357,359A respectively. We found that both mutants bound phospholipids at low Ca2+ concentrations and were membrane-associated in resting neurons, thus mimicking a Ca2+-activated state. Their overexpression in hippocampal primary cultured neurons had similar effects on spontaneous and evoked release, inducing high mEPSC frequencies and increased short-term depression. Together, these data suggest that the DN and 6A mutants both act as gain-of-function mutants at resting conditions.

scholarly journals Tek (Tie2) is not required for cardiovascular development in zebrafish

Development ◽  
2020 ◽  
Vol 147 (19) ◽  
pp. dev193029 ◽  
Author(s):  
Zhen Jiang ◽  
Claudia Carlantoni ◽  
Srinivas Allanki ◽  
Ingo Ebersberger ◽  
Didier Y. R. Stainier
Keyword(s):  
Binding Site ◽  
Lymphatic Vessel ◽  
Vascular Malformations ◽  
Premature Termination Codon ◽  
Cardiovascular Development ◽  
Loss Of Function ◽  
Cardiovascular Defects ◽  
Vessel Development ◽  
Phylogenetic Profiling ◽  
Target Effects

ABSTRACTAngiopoietin/TIE signalling plays a major role in blood and lymphatic vessel development. In mouse, Tek (previously known as Tie2) mutants die prenatally due to a severely underdeveloped cardiovascular system. In contrast, in zebrafish, previous studies have reported that although embryos injected with tek morpholinos (MOs) exhibit severe vascular defects, tek mutants display no obvious vascular malformations. To further investigate the function of zebrafish Tek, we generated a panel of loss-of-function tek mutants, including RNA-less alleles, an allele lacking the MO-binding site, an in-frame deletion allele and a premature termination codon-containing allele. Our data show that all these mutants survive to adulthood with no obvious cardiovascular defects. MO injections into tek mutants lacking the MO-binding site or the entire tek locus cause similar vascular defects to those observed in MO-injected +/+ siblings, indicating off-target effects of the MOs. Surprisingly, comprehensive phylogenetic profiling and synteny analyses reveal that Tek was lost in the largest teleost clade, suggesting a lineage-specific shift in the function of TEK during vertebrate evolution. Altogether, these data show that Tek is dispensable for zebrafish development, and probably dispensable in most teleost species.

scholarly journals Bi-allelic GAD1 variants cause a neonatal onset syndromic developmental and epileptic encephalopathy

Brain ◽  
2020 ◽  
Vol 143 (5) ◽  
pp. 1447-1461 ◽  
Author(s):  
Nicolas Chatron ◽  
Felicitas Becker ◽  
Heba Morsy ◽  
Miriam Schmidts ◽  
Katia Hardies ◽  
...  
Keyword(s):  
Cleft Palate ◽  
Epileptic Encephalopathy ◽  
Allelic Loss ◽  
Loss Of Function ◽  
Seizure Onset ◽  
Joint Contractures ◽  
Epileptic Encephalopathies ◽  
Genomic Technologies ◽  
Pes Equinovarus ◽  
Modern Genomic

Abstract Developmental and epileptic encephalopathies are a heterogeneous group of early-onset epilepsy syndromes dramatically impairing neurodevelopment. Modern genomic technologies have revealed a number of monogenic origins and opened the door to therapeutic hopes. Here we describe a new syndromic developmental and epileptic encephalopathy caused by bi-allelic loss-of-function variants in GAD1, as presented by 11 patients from six independent consanguineous families. Seizure onset occurred in the first 2 months of life in all patients. All 10 patients, from whom early disease history was available, presented with seizure onset in the first month of life, mainly consisting of epileptic spasms or myoclonic seizures. Early EEG showed suppression-burst or pattern of burst attenuation or hypsarrhythmia if only recorded in the post-neonatal period. Eight patients had joint contractures and/or pes equinovarus. Seven patients presented a cleft palate and two also had an omphalocele, reproducing the phenotype of the knockout Gad1−/− mouse model. Four patients died before 4 years of age. GAD1 encodes the glutamate decarboxylase enzyme GAD67, a critical actor of the γ-aminobutyric acid (GABA) metabolism as it catalyses the decarboxylation of glutamic acid to form GABA. Our findings evoke a novel syndrome related to GAD67 deficiency, characterized by the unique association of developmental and epileptic encephalopathies, cleft palate, joint contractures and/or omphalocele.

scholarly journals Mutagenesis Analysis of ABCB8 Gene Promoter of Danio rerio

2021 ◽  
Vol 4 (1) ◽  
pp. a1-8
Author(s):  
PEI NI LAI ◽  
LEONARD WHYE KIT LIM ◽  
HUNG HUI CHUNG
Keyword(s):  
Binding Site ◽  
Danio Rerio ◽  
Gene Promoter ◽  
Promoter Sequence ◽  
Loss Of Function ◽  
Intracellular Iron ◽  
Heme Transport ◽  
Promoter Gene ◽  
Reverse Primer ◽  
Specific Pair

The ABCB8 is one of the members under the ABCB subfamily of ATP-Binding Cassette (ABC) transporter which possess the ability in regulating the intracellular iron and heme transport. The loss of function mutation of ABCB8 gene leads to iron and heme accumulation in the cell which is highly toxic to human. However, the information regarding the expression regulation of this gene remains scarce. Hence, the objectives of this project are to determine the transcription factors binding site (TFBS) of ABCB8 and to identify the transcriptional roles of the cis-elements through mutagenesis analysis. To examine this, total genomic DNA was extracted from Danio rerio and the promoter sequence was isolated by using specific pair of primers through polymerase chain reaction (PCR). The sample was sent for DNA sequencing and the result showed 98% similarities to the zebrafish DNA sequence from clone DKEYP-87A6 in linkage group 24. Besides, the TFBS was studied in aspect of TFBS abundance, TFBS composition and TFBS distribution. The two most abundant TFBSs based on liver-specific profile were HNF-3β and C/EBPβ, with 38 and 39 binding sites, respectively. The sequence of ABCB8 promoter gene was mutated through substitution of the AP-1 binding site at location 535 with other nucleotides by using a pair of mutagenic primers (forward primer: 5’-TGGGGGTTTAGATATTGAAAC-3’; reverse primer: 5’-AACTCGC ATACATTTCAGTCATC-3’). This result may benefit the development of new diagnostics and therapeutics for iron-associated disorder.

scholarly journals Doc2b Ca2+-binding site mutants act as a gain of function at rest and loss of function during neuronal activity

2019 ◽  
Author(s):  
Quentin Bourgeois-Jaarsma ◽  
Matthijs Verhage ◽  
Alexander J. Groffen
Keyword(s):  
Binding Site ◽  
Neuronal Activity ◽  
Neurotransmitter Release ◽  
Action Potentials ◽  
Vesicle Fusion ◽  
Primary Neurons ◽  
Loss Of Function ◽  
Short Term ◽  
Gain Of Function ◽  
Activated State

AbstractCommunication between neurons involves presynaptic neurotransmitter release which can be evoked by action potentials or occur spontaneously as a result of stochastic vesicle fusion. The Ca2+-binding double C2 proteins Doc2a and –b regulate both spontaneous and asynchronous evoked release, but the mechanism remains unclear. Here, we compared wildtype Doc2b with two Ca2+ binding site mutants named DN and 6A, respectively considered gain-and loss-of function mutants and carrying the substitutions D218,220N or D163,218,220,303,357,359A. We found that both mutants bound phospholipids at low free Ca2+ concentrations and were membrane-associated in neurons at rest, mimicking a Ca2+ activated state. Their overexpression in hippocampal primary neurons culture had similar effects on spontaneous and evoked release, inducing higher mEPSC frequencies and increased short-term depression. Together, these data suggest that the DN and 6A mutants both act as gain-of-function mutants at resting conditions but as loss-of-function during neuronal activity.

scholarly journals Antisense oligonucleotide-based therapeutic strategy for progranulin-deficient frontotemporal dementia

2022 ◽  
Author(s):  
Geetika Aggarwal ◽  
Subhashis Banerjee ◽  
Spencer A. Jones ◽  
Monica D. Pavlack ◽  
Yousri Benchaar ◽  
...  
Keyword(s):  
Binding Site ◽  
Frontotemporal Dementia ◽  
Antisense Oligonucleotide ◽  
Antisense Oligonucleotides ◽  
Therapeutic Strategy ◽  
Neurological Diseases ◽  
Therapeutic Modality ◽  
Loss Of Function ◽  
Common Cause ◽  
Protein Levels

Loss-of-function GRN mutations result in progranulin haploinsufficiency and are a common cause of frontotemporal dementia (FTD). Antisense oligonucleotides (ASOs) are emerging as a promising therapeutic modality for neurological diseases, but ASO-based strategies for increasing target protein levels are still relatively limited. Here, we report the use of ASOs to increase progranulin protein levels by targeting the miR-29b binding site in the 3′ UTR of the GRN mRNA, resulting in increased translation.

scholarly journals Loss-of-Function GRHL3 Variants Detected in African Patients with Isolated Cleft Palate

2017 ◽  
Vol 97 (1) ◽  
pp. 41-48 ◽  
Author(s):  
M.A. Eshete ◽  
H. Liu ◽  
M. Li ◽  
W.L. Adeyemo ◽  
L.J.J Gowans ◽  
...  
Keyword(s):  
Cleft Palate ◽  
Cleft Lip ◽  
De Novo ◽  
Phosphorylation Site ◽  
Dominant Negative ◽  
Loss Of Function ◽  
De Novo Mutations ◽  
Sumoylation Site ◽  
Genetic Etiology

In contrast to the progress that has been made toward understanding the genetic etiology of cleft lip with or without cleft palate, relatively little is known about the genetic etiology for cleft palate only (CPO). A common coding variant of grainyhead like transcription factor 3 ( GRHL3) was recently shown to be associated with risk for CPO in Europeans. Mutations in this gene were also reported in families with Van der Woude syndrome. To identify rare mutations in GRHL3 that might explain the missing heritability for CPO, we sequenced GRHL3 in cases of CPO from Africa. We recruited participants from Ghana, Ethiopia, and Nigeria. This cohort included case-parent trios, cases and other family members, as well as controls. We sequenced exons of this gene in DNA from a total of 134 nonsyndromic cases. When possible, we sequenced them in parents to identify de novo mutations. Five novel mutations were identified: 2 missense (c.497C>A; p.Pro166His and c.1229A>G; p.Asp410Gly), 1 splice site (c.1282A>C p.Ser428Arg), 1 frameshift (c.470delC; p.Gly158Alafster55), and 1 nonsense (c.1677C>A; p.Tyr559Ter). These mutations were absent from 270 sequenced controls and from all public exome and whole genome databases, including the 1000 Genomes database (which includes data from Africa). However, 4 of the 5 mutations were present in unaffected mothers, indicating that their penetrance is incomplete. Interestingly, 1 mutation damaged a predicted sumoylation site, and another disrupted a predicted CK1 phosphorylation site. Overexpression assays in zebrafish and reporter assays in vitro indicated that 4 variants were functionally null or hypomorphic, while 1 was dominant negative. This study provides evidence that, as in Caucasian populations, mutations in GRHL3 contribute to the risk of nonsyndromic CPO in the African population.

scholarly journals Total colonic aganglionosis and cleft palate in a newborn with Janus-cysteine 618 mutation of RET proto-oncogene: a case report

2020 ◽  
Vol 46 (1) ◽  
Author(s):  
Ingrid Anne Mandy Schierz ◽  
Marcello Cimador ◽  
Mario Giuffrè ◽  
Claudia Maria Aiello ◽  
Vincenzo Antona ◽  
...  
Keyword(s):  
Cleft Palate ◽  
Retinal Dystrophy ◽  
Hirschsprung Disease ◽  
Copy Number Variations ◽  
Chromosomal Anomalies ◽  
Single Mutation ◽  
Loss Of Function ◽  
Ileal Loop ◽  
Total Colonic Aganglionosis ◽  
Developmental Abnormalities

Abstract Background Hirschsprung disease, the most important congenital colonic dysmotility in children results from neural crest migration, differentiation, proliferation, or apoptosis defects where the rearranged during transfection (RET)-Protooncogene pathway has a central role. Although palatal and retinal anomalies in the context of chromosomopathies and some mono−/oligogenic syndromes are reported associated with Hirschsprung disease the role of inactivating RET mutations in these cases is not clarified. Case presentation We report on a dysmorphic newborn with cleft palate and palatal synechia, who showed intestinal obstruction after 24 h of life. Transient ileostomy and surgical biopsies were performed to diagnose aganglionosis of the colon and last ileal loop. No chromosomal anomalies or copy number variations were found. We identified a paternal heterozygous germline mutation c.1852 T > C, which results in the substitution of cysteine by arginine in the RET-receptor tyrosine kinase (p.C618R mutation). There was no family history of Hirschsprung disease, but the father underwent surgery for medullary thyroid carcinoma and was affected by retinal dystrophy. Conclusions The occurrence of Hirschsprung disease and carcinoma shows how a single mutation may be responsible for adverse effects: gain and loss of function of the same receptor. Furthermore, it would be interesting to study its dual role in face and retina embryology, and to extend targeted investigations of RET hotspots in these developmental abnormalities to facilitate counselling, follow-up, and tumor prevention. Complex surgical procedures and genetic testing as well as socio-economic impact are a challenge for familiar compliance.

scholarly journals Calcium Sensitive Allostery Regulates the PI(4,5)P2 Binding Site of the Dysferlin C2A Domain

2021 ◽  
Author(s):  
Shauna C. Otto ◽  
Patrick N. Reardon ◽  
Tanushri M. Kumar ◽  
Chapman J. Kuykendall ◽  
Colin P. Johnson
Keyword(s):  
Binding Site ◽  
Calcium Binding ◽  
Binding Pocket ◽  
Resonance Spectroscopy ◽  
Loss Of Function ◽  
Unknown Mechanism ◽  
C2 Domains ◽  
Calcium Dependent ◽  
N Terminus ◽  
C2a Domain

C2 domains are the second-most abundant calcium binding module in the proteome. Activity of the muscular dystrophy associated protein dysferlin is dependent on the C2A domain at the N-terminus of the protein, which couples calcium and PI(4,5)P2 binding through an unknown mechanism. Using solution state nuclear magnetic resonance spectroscopy we confirm the phosphoinositide binding site for the domain and find that calcium binding attenuates millisecond to microsecond motions at both in the calcium binding loops and the concave face of the C2A, including a portion of the phosphoinositide binding site. Our results support a model whereby increasing calcium concentrations shift the phosphoinositide binding pocket of C2A into a binding-competent state, allowing for calcium dependent membrane targeting. This model contrasts with the canonical mechanism for C2 domain-phosphoinositide interaction and provides a basis for how pathogenic mutations in the C2A domain result in loss of function and disease.

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