scholarly journals Predominant and novel de novo variants in 29 individuals with ALG13 deficiency: Clinical description, biomarker status, biochemical analysis, and treatment suggestions

2020 ◽  
Vol 43 (6) ◽  
pp. 1333-1348 ◽  
Author(s):  
Bobby G. Ng ◽  
Erik A. Eklund ◽  
Sergey A. Shiryaev ◽  
Yin Y. Dong ◽  
Mary‐Alice Abbott ◽  
...  
Keyword(s):  
Biochemical Analysis ◽  
De Novo ◽  
Clinical Description

Fluorescent phospholipids preferentially accumulate in sub-tegumental cells of schistosomula of Schistosoma mansoni

1992 ◽  
Vol 103 (3) ◽  
pp. 823-830 ◽  
Author(s):  
S.T. Furlong ◽  
K.S. Thibault ◽  
R.A. Rogers
Keyword(s):  
Cellular Network ◽  
Biochemical Analysis ◽  
Phosphatidyl Ethanolamine ◽  
De Novo ◽  
Cell Types ◽  
Host Immunity ◽  
Epifluorescence Microscopy ◽  
Specific Cell ◽  
Back Exchange ◽  
Intact Molecule

Schistosomes do not make sterols or fatty acids de novo and thus require host lipids for survival. The acquisition of host lipids may also be an important factor in the schistosome's defense from host immunity; however, little is known about the regulation of this process. Here we have examined binding of radiolabeled and fluorescently labeled liposomes to schistosomula, and followed incorporation of fluorescent phospholipids into the worm by both morphological and biochemical methods. Saturable binding of radiolabeled phosphatidylcholine containing liposomes was observed and epifluorescence microscopy showed binding of C6-NBD-phosphatidylcholine (C6-NBD-PC), C12-NBD-phosphatidylcholine (C12-NBD-PC) and C6-NBD-phosphatidyl-ethanolamine (C6-NBD-PE) containing liposomes on the surface of the parasite. Following back-exchange with unlabeled liposomes, NBD-PC and NBD-PE were observed to be preferentially incorporated into specific cell types within the worm. Furthermore, cells which had accumulated the fluorescent lipid formed an interconnecting cellular network immediately below the tegument, identified as cytons. By contrast, fluorescein-PE was found only on the surface of the parasite and in the gut but not in the cytons. Biochemical analysis demonstrated that > 90% of the C6-NBD-PC and C12-NBD-PC remained as the intact molecule after a one hour incubation with the parasite, but that greater than 70% of the NBD-PE was converted to other lipids. These studies demonstrate that incorporation of phospholipid analogs into schistosomula can be followed morphologically and biochemically. As there was little localization of NBD-PE or NBD-PC in the gut, these analogs must be assimilated by crossing the tegument.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural insights into the catalytic mechanism of the yeast pyridoxal 5-phosphate synthase Snz1

2010 ◽  
Vol 432 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Xuan Zhang ◽  
Yan-Bin Teng ◽  
Jian-Ping Liu ◽  
Yong-Xing He ◽  
Kang Zhou ◽  
...  
Keyword(s):  
Binding Site ◽  
Vitamin B6 ◽  
Active Sites ◽  
Biochemical Analysis ◽  
Catalytic Mechanism ◽  
De Novo ◽  
Active Form ◽  
Dihydroxyacetone Phosphate ◽  
Final Destination ◽  
Structural Insights

In most eubacteria, fungi, apicomplexa, plants and some metazoans, the active form of vitamin B6, PLP (pyridoxal 5-phosphate), is de novo synthesized from three substrates, R5P (ribose 5-phosphate), DHAP (dihydroxyacetone phosphate) and ammonia hydrolysed from glutamine by a complexed glutaminase. Of the three active sites of DXP (deoxyxylulose 5-phosphate)independent PLP synthase (Pdx1), the R5P isomerization site has been assigned, but the sites for DHAP isomerization and PLP formation remain unknown. In the present study, we present the crystal structures of yeast Pdx1/Snz1, in apo-, G3P (glyceraldehyde 3-phosphate)- and PLP-bound forms, at 2.3, 1.8 and 2.2 Å (1 Å=0.1 nm) respectively. Structural and biochemical analysis enabled us to assign the PLP-formation site, a G3P-binding site and a G3P-transfer site. We propose a putative catalytic mechanism for Pdx1/Snz1 in which R5P and DHAP are isomerized at two distinct sites and transferred along well-defined routes to a final destination for PLP synthesis.

Array-CGH analysis and clinical description of 2q37.3 de novo subtelomeric deletion

2007 ◽  
Vol 50 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Sofia Kitsiou-Tzeli ◽  
Carolina Sismani ◽  
Marios Ioannides ◽  
Stavros Bashiardes ◽  
Andria Ketoni ◽  
...  
Keyword(s):  
Array Cgh ◽  
De Novo ◽  
Subtelomeric Deletion ◽  
Clinical Description

scholarly journals Unproven causal relation between a de novo NKX2.5 insertion and left ventricular noncompaction

2019 ◽  
pp. 04-05
Author(s):  
Finsterer J ◽  
Stöllberger C
Keyword(s):  
De Novo ◽  
Causal Relation ◽  
Neuromuscular Disorders ◽  
Family Members ◽  
Left Ventricular ◽  
Exon 2 ◽  
Ventricular Noncompaction ◽  
Septal Defects ◽  
Translation Start ◽  
Clinical Description

In their article, Ouyong et al. reported about a three-generation family, of which three members carried a heterozygous 2bp insertion at c.512 from the translation start point in exon 2 of the NKX2.5 gene [1]. Mutations in the NKX2.5 have been shown to be associated with atrial septal defects (ASDs), congenital heart disease (CHD), and occasionally left-ventricular hypertrabeculation / noncompaction (LVHT) [2-4]. We have the following comments and concerns. Though three family members carried the mutation only one of them (III/2) presented with (LVHT). How do the authors explain this finding particularly with regard to the proposed causal relation between LVHT and the mutation? How to explain the interfamilial heterogeneity? Were family members not carrying the mutation also screened for LVHT? Since LVHT frequently occurs familiarly and since a causal relation between the mutation and LVHT remains unproven, LVHT might have been due to other causes. Since LVHT is frequently associated with neuromuscular disorders (NMDs) [5], it is worthwhile to investigate affected and non-affected family members for clinically manifesting or subclinical NMD. There is no comprehensive clinical description of the presented cases. Were there any indications for an extra-cardiac disease?

scholarly journals The roles of a flagellar HSP40 ensuring rhythmic beating

2019 ◽  
Vol 30 (2) ◽  
pp. 228-241 ◽  
Author(s):  
Xiaoyan Zhu ◽  
Emiliya Poghosyan ◽  
Lenka Rezabkova ◽  
Bridget Mehall ◽  
Hitoshi Sakakibara ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Biochemical Analysis ◽  
De Novo ◽  
Electron Tomography ◽  
Donor Cell ◽  
Central Pair ◽  
Radial Spoke ◽  
Cryo Electron Tomography ◽  
Rigid Conformation ◽  
Mechanical Feedback

HSP40s are regarded as cochaperones, perpetually shuttling client polypeptides to HSP70s for refolding. However, many HSP40s that are central for disparate processes diverge from this paradigm. To elucidate the noncanonical mechanisms, we investigated HSP40 in the radial spoke (RS) complex in flagella. Disruption of the gene by the MRC1 transposon in Chlamydomonas resulted in jerky flagella. Traditional electron microscopy, cryo-electron tomography, and sub-tomogram analysis revealed RSs of various altered morphologies that, unexpectedly, differed between the two RS species. This indicates that HSP40 locks the RS into a functionally rigid conformation, facilitating its interactions with the adjacent central pair apparatus for transducing locally varied mechanical feedback, which permits rhythmic beating. Missing HSP40, like missing RSs, could be restored in a tip-to-base direction when HSP40 mutants fused with a HSP40 donor cell. However, without concomitant de novo RS assembly, the repair was exceedingly slow, suggesting HSP40/RS-coupled intraflagellar trafficking and assembly. Biochemical analysis and modeling uncovered spoke HSP40’s cochaperone traits. On the basis of our data, we propose that HSP40 accompanies its client RS precursor when traveling to the flagellar tip. Upon arrival, both refold in concert to assemble into the mature configuration. HSP40’s roles in chaperoning and structural maintenance shed new light on its versatility and flagellar biology.

scholarly journals Screening of 50 Cypriot Patients with Autism Spectrum Disorders or Autistic Features Using 400K Custom Array-CGH

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Ludmila Kousoulidou ◽  
Maria Moutafi ◽  
Paola Nicolaides ◽  
Stavros Hadjiloizou ◽  
Christos Christofi ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Developmental Disorders ◽  
Array Cgh ◽  
De Novo ◽  
Autism Spectrum ◽  
Copy Number Variations ◽  
Comparative Genomic ◽  
Normal Individuals ◽  
Spectrum Disorders ◽  
Clinical Description

Autism spectrum disorders (ASDs) comprise a distinct entity of neurodevelopmental disorders with a strong genetic component. Despite the identification of several candidate genes and causative genomic copy number variations (CNVs), the majority of ASD cases still remain unresolved. We have applied microarray-based comparative genomic hybridization (array-CGH) using Agilent 400K custom array in the first Cyprus population screening for identification of ASD-associated CNVs. A cohort of 50 ASD patients (G1), their parents (G2), 50 ethnically matched normal controls (G3), and 80 normal individuals having children with various developmental and neurological conditions (G4) were tested. As a result, 14 patients were found to carry 20 potentially causative aberrations, two of which werede novo. Comparison of the four population groups revealed an increased rate of rare disease-associated variants in normal parents of children with autism. The above data provided additional evidence, supporting the complexity of ASD aetiology in comparison to other developmental disorders involving cognitive impairment. Furthermore, we have demonstrated the rationale of a more targeted approach combining accurate clinical description with high-resolution population-oriented genomic screening for defining the role of CNVs in autism and identifying meaningful associations on the molecular level.

scholarly journals Biochemical phenotype and origin of the three most common beta-thalassemia mutations in Serbia

2004 ◽  
Vol 23 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Jelena Poznanic ◽  
Ljubica Perisic ◽  
Jelena Urosevic ◽  
Branka Petrucev ◽  
Tatjana Djureinovic ◽  
...  
Keyword(s):  
Biochemical Analysis ◽  
De Novo ◽  
Globin Gene ◽  
Initial Step ◽  
Beta Thalassemia ◽  
Background Characteristic ◽  
Biochemical Phenotype ◽  
Biochemical Characteristics ◽  
Dna Characterization

Molecular (DNA) characterization of thalassemia is the most reliable methodology for the diagnosis of this group of diseases. As thalassemias are very heterogeneous, hematological data and additional biochemical analysis are essential for their differential diagnosis. In this paper we present hematological and biochemical characteristics of the carriers of three most common beta-thalassemia mutations in Serbia (Hb Lepore, b?39 and b+IVS-I-110), to be taken into consideration as the initial step of the diagnostic approach to the thalassemia patients. Also, this paper represents a detailed survey of the diversity of b-globin gene haplotypes in carriers of the most common b-thalassemia mutations and normal betaA/betaA individuals of Serbian descent. A novel haplotype associated with Hb Lepore-Boston-Washington gene has been identified in Serbian population. These data support the hypothesis of multicentric origin of this mutation. The mutation has arised de novo in the chromosomal background characteristic for Serbian population. Additionally, we have shown that two most common Mediterranean mutations, b?39 and b+ IVS-I-110, have probably been introduced into Serbian population from Italy and Turkey, respectively, through historically documented migrations and settlements.

scholarly journals Structural studies reveal a ring-shaped architecture of deep-sea vent phage NrS-1 polymerase

2020 ◽  
Vol 48 (6) ◽  
pp. 3343-3355
Author(s):  
Xi Chen ◽  
Shichen Su ◽  
Yiqing Chen ◽  
Yanqing Gao ◽  
Yangyang Li ◽  
...  
Keyword(s):  
Deep Sea ◽  
Biochemical Analysis ◽  
De Novo ◽  
Structural Similarity ◽  
Helicase Domain ◽  
Structural Studies ◽  
Dna Polymerization ◽  
C Terminus ◽  
And Function

Abstract NrS-1 is the first known phage that can infect Epsilonproteobacteria, one of the predominant primary producers in the deep-sea hydrothermal vent ecosystems. NrS-1 polymerase is a multidomain enzyme and is one key component of the phage replisome. The N-terminal Prim/Pol and HBD domains are responsible for DNA polymerization and de novo primer synthesis activities of NrS-1 polymerase. However, the structure and function of the C-terminus (CTR) of NrS-1 polymerase are poorly understood. Here, we report two crystal structures, showing that NrS-1 CTR adopts one unique hexameric ring-shaped conformation. Although the central helicase domain of NrS-1 CTR shares structural similarity with the superfamily III helicases, the folds of the Head and Tail domains are completely novel. Via mutagenesis and in vitro biochemical analysis, we identified many residues important for the helicase and polymerization activities of NrS-1 polymerase. In addition to NrS-1 polymerase, our study may also help us identify and understand the functions of multidomain polymerases expressed by many NrS-1 related phages.

scholarly journals Microcephaly-capillary malformation syndrome: the newly reported cases

2020 ◽  
pp. 31-37
Author(s):  
OA Shchagina ◽  
NA Semenova ◽  
LA Bessonova ◽  
EA Larshina ◽  
NS Beskorovainiy ◽  
...  
Keyword(s):  
Biochemical Analysis ◽  
De Novo ◽  
Genetic Disorders ◽  
Rflp Analysis ◽  
Pedigree Analysis ◽  
Gene Variants ◽  
Malformation Syndrome ◽  
Capillary Malformation ◽  
Galt Gene ◽  
Autosomal Recessive Manner

Microcephaly-capillary malformation syndrome (MICCAP: OMIM 614261) is a severe monogenic disorder inherited in an autosomal recessive manner caused by mutations in the STAMBP gene. There are less than 20 published cases of the syndrome to date. The paper reports three new cases of rare MICCAP syndrome. The cause of the disorder was confirmed in three affected individuals from two unrelated families by pedigree analysis, biochemical analysis, RFLP analysis and automated Sanger sequencing. The two brothers were homozygous for the potentially pathogenic STAMBP gene variant c.188A>G (p.Tyr63Cys). Clinical phenotype of the girl from the second family resulted from the combination of two genetic disorders: galactosemia caused by the compound heterozygosity for the pathogenic GALT gene variants (c.563A>G and c.855G>T), and MICCAP caused by the STAMBP gene variants (c.204-5c>g and с.668_669delCA), one of which originated de novo. The prevalence of microcephaly-capillary malformation syndrome in Russia is evaluated, it is one per 120,000 people (CI: 1/356 724–1/62 691). The carrier frequency is one per 173 people. The target STAMBP gene analysis makes the genetic confirmation of the MICCAP syndrome quicklier. When determining the tactics of diagnosis and therapy in each particular case, the possibility of combination of two rare genetic disorders in one patient should be considered.

scholarly journals Trypsin Cleavage Stabilizes the Rotavirus VP4 Spike

2001 ◽  
Vol 75 (13) ◽  
pp. 6052-6061 ◽  
Author(s):  
Sue E. Crawford ◽  
Sharmila K. Mukherjee ◽  
Mary K. Estes ◽  
Jeffery A. Lawton ◽  
Andrea L. Shaw ◽  
...  
Keyword(s):  
Biochemical Analysis ◽  
De Novo ◽  
Protein Composition ◽  
Structural Basis ◽  
Trypsin Treatment ◽  
Animal Group ◽  
Virus Particles ◽  
Before And After ◽  
Group A Rotaviruses ◽  
Group A

ABSTRACT Trypsin enhances rotavirus infectivity by an unknown mechanism. To examine the structural basis of trypsin-enhanced infectivity in rotaviruses, SA11 4F triple-layered particles (TLPs) grown in the absence (nontrypsinized rotavirus [NTR]) or presence (trypsinized rotavirus [TR]) of trypsin were characterized to determine the structure, the protein composition, and the infectivity of the particles before and after trypsin treatment. As expected, VP4 was not cleaved in NTR particles and was cleaved into VP5∗ and VP8∗ in TR particles. However, surprisingly, while the VP4 spikes were clearly visible and well ordered in the electron cryomicroscopy reconstructions of TR TLPs, they were totally absent in the reconstructions of NTR TLPs. Biochemical analysis with radiolabeled particles indicated that the stoichiometry of the VP4 in NTR particles was the same as that in TR particles and that the VP8∗ portion of NTR, but not TR, particles is susceptible to further proteolysis by trypsin. Taken together, these structural and biochemical data show that the VP4 spikes in the NTR TLPs are icosahedrally disordered and that they are conformationally different. Structural studies on the NTR TLPs after trypsin treatment showed that spike structure could be partially recovered. Following additional trypsin treatment, infectivity was enhanced for both NTR and TR particles, but the infectivity of NTR remained 2 logs lower than that of TR particles. Increased infectivity in these particles corresponded to additional cleavages in VP5∗, at amino acids 259, 583, and putatively 467, which are conserved in all P serotypes of human and animal group A rotaviruses and also corresponded with a structural change in VP7. These biochemical and structural results show that trypsin cleavage imparts order to VP4 spikes on de novo synthesized virus particles, and these ordered spikes make virus entry into cells more efficient.

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