scholarly journals Large transient capacitive currents in wild-type lysosomal Cl−/H+ antiporter ClC-7 and residual transport activity in the proton glutamate mutant E312A

2020 ◽  
Vol 153 (1) ◽  
Author(s):  
Michael Pusch ◽  
Giovanni Zifarelli
Keyword(s):  
Storage Disease ◽  
Intermediate Phenotype ◽  
Mouse Line ◽  
Lysosomal Storage ◽  
Transport Activity ◽  
Wild Type ◽  
Transport Cycle ◽  
Residual Transport ◽  
Cl Channels ◽  
External Ph

ClC-7 is a lysosomal 2 Cl−/1 H+ antiporter of the CLC protein family, which comprises Cl− channels and other Cl−/H+ antiporters. Mutations in ClC-7 and its associated β subunit Ostm1 lead to osteopetrosis and lysosomal storage disease in humans and mice. Previous studies on other mammalian CLC transporters showed that mutations of a conserved, intracellularly located glutamate residue, the so-called proton glutamate, abolish steady-state transport activity but increase transient capacitive currents associated with partial reactions of the transport cycle. In contrast, we observed large, transient capacitive currents for the wild-type ClC-7, which depend on external pH and internal, but not external, Cl−. Very similar transient currents were observed for the E312A mutant of the proton glutamate. Interestingly, and unlike in other mammalian CLC transporters investigated so far, the E312A mutation strongly reduces, but does not abolish, stationary transport currents, potentially explaining the intermediate phenotype observed in the E312A mouse line.

scholarly journals Multiple Paths for Nonphysiological Transport of K+ in Escherichia coli

2004 ◽  
Vol 186 (13) ◽  
pp. 4238-4245 ◽  
Author(s):  
Ed T. Buurman ◽  
Debbie McLaggan ◽  
Josef Naprstek ◽  
Wolfgang Epstein
Keyword(s):  
Escherichia Coli ◽  
Substrate Specificity ◽  
Driving Force ◽  
Physiological Function ◽  
Transport Systems ◽  
Transport Activity ◽  
Wild Type ◽  
Multiple Paths ◽  
Oligopeptide Permease ◽  
External Ph

ABSTRACT Mutants of Escherichia coli lacking all of the known saturable K+ transport systems, “triple mutants,” require elevated K+ concentrations for growth. K+ transport activity in such mutants, called TrkF activity, has low substrate specificity and a low rate that increases with increasing external pH. Attempts to isolate mutants requiring even higher concentrations of K+ failed, implying that either TrkF is essential or is composed of multiple minor K+ transport activities. Instead, we sought mutations that allowed triple mutants to grow at lower K+ concentrations. Mutations so identified include ones altering MscL, the large mechanosensitive channel, or Opp, the oligopeptide permease. However, a possible contribution of wild-type Opp and MscL to TrkF activity was not proven. In contrast, expression of wild-type ProP, TrkG, and TrkH proteins increased uptake when encoded on multicopy plasmids. In all of these situations, the driving force for K+ appeared to be the transmembrane electric potential, and in most cases substrate specificity was low; these are characteristics of TrkF activity. These results support the view that TrkF is composed of multiple, “aberrant” K+ transport activities, i.e., paths that, regardless of their physiological function, allow K+ to cross the cell membrane by a uniport process.

Is there a role for scintigraphic imaging of bone manifestations in Gaucher disease?

2008 ◽  
Vol 47 (06) ◽  
pp. 239-247 ◽  
Author(s):  
S. Kohlfürst ◽  
H. J. Gallowitsch ◽  
E. Kresnik ◽  
P. Lind ◽  
A. B. Mehta ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Lysosomal Storage Disease ◽  
Gaucher Disease ◽  
Storage Disease ◽  
Lysosomal Storage ◽  
Scintigraphic Imaging ◽  
Imaging Methods ◽  
X Ray ◽  
Deficient Activity

SummaryGaucher disease is the most prevalent inherited, lysosomal storage disease and is caused by deficient activity of the enzyme β-glucocerebrosidase. Bone and bone marrow alterations are frequent in the most prevalent non-neuronopathic form of Gaucher disease. Imaging of bone manifestations in Gaucher disease is performed by a variety of imaging methods, conventional X-ray and MRI as the most frequently and most important ones. However, different modalities of scintigraphic imaging have also been used. This article gives an overview on scintigraphic imaging with respect to bone manifestations in Gaucher disease discussing the advantages and limitations of scintigraphic imaging in comparison to other imaging methods.

scholarly journals Identification of a novel homozygous loss-of-function mutation in FUCA1 gene causing severe fucosidosis: A case report

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110059
Author(s):  
Xinwen Zhang ◽  
Shaozhi Zhao ◽  
Hongwei Liu ◽  
Xiaoyan Wang ◽  
Xiaolei Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lysosomal Storage Disorder ◽  
Autosomal Recessive ◽  
Signs And Symptoms ◽  
Lysosomal Storage ◽  
Loss Of Function ◽  
Wild Type ◽  
Single Nucleotide ◽  
Whole Exome ◽  
Exon 1

Fucosidosis is a rare lysosomal storage disorder characterized by deficiency of α-L-fucosidase with an autosomal recessive mode of inheritance. Here, we describe a 4-year-old Chinese boy with signs and symptoms of fucosidosis but his parents were phenotypically normal. Whole exome sequencing (WES) identified a novel homozygous single nucleotide deletion (c.82delG) in the exon 1 of the FUCA1 gene. This mutation will lead to a frameshift which will result in the formation of a truncated FUCA1 protein (p.Val28Cysfs*105) of 132 amino acids approximately one-third the size of the wild type FUCA1 protein (466 amino acids). Both parents were carrying the mutation in a heterozygous state. This study expands the mutational spectrum of the FUCA1 gene associated with fucosidosis and emphasises the benefits of WES for accurate and timely clinical diagnosis of this rare disease.

scholarly journals α-Galactosidase A Augmentation by Non-Viral Gene Therapy: Evaluation in Fabry Disease Mice

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 771
Author(s):  
Julen Rodríguez-Castejón ◽  
Ana Alarcia-Lacalle ◽  
Itziar Gómez-Aguado ◽  
Mónica Vicente-Pascual ◽  
María Ángeles Solinís Aspiazu ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Fabry Disease ◽  
Viral Vector ◽  
Viral Gene ◽  
Lysosomal Storage ◽  
Wild Type ◽  
Dose Administration ◽  
Viral Gene Therapy ◽  
Liver Transaminases ◽  
Low Levels

Fabry disease (FD) is a monogenic X-linked lysosomal storage disorder caused by a deficiency in the lysosomal enzyme α-Galactosidase A (α-Gal A). It is a good candidate to be treated with gene therapy, in which moderately low levels of enzyme activity should be sufficient for clinical efficacy. In the present work we have evaluated the efficacy of a non-viral vector based on solid lipid nanoparticles (SLN) to increase α-Gal A activity in an FD mouse model after intravenous administration. The SLN-based vector incremented α-Gal A activity to about 10%, 15%, 20% and 14% of the levels of the wild-type in liver, spleen, heart and kidney, respectively. In addition, the SLN-based vector significantly increased α-Gal A activity with respect to the naked pDNA used as a control in plasma, heart and kidney. The administration of a dose per week for three weeks was more effective than a single-dose administration. Administration of the SLN-based vector did not increase liver transaminases, indicative of a lack of toxicity. Additional studies are necessary to optimize the efficacy of the system; however, these results reinforce the potential of lipid-based nanocarriers to treat FD by gene therapy.

Neonatal ascites due to lysosomal storage disease.

Radiology ◽  
1983 ◽  
Vol 149 (2) ◽  
pp. 463-467 ◽  
Author(s):  
A Daneman ◽  
D Stringer ◽  
B J Reilly
Keyword(s):  
Lysosomal Storage Disease ◽  
Storage Disease ◽  
Lysosomal Storage

Loss of wild-type carrier-mediatedL-carnitine transport activity in hepatocytes of juvenile visceral steatosis mice

Hepatology ◽  
1999 ◽  
Vol 30 (4) ◽  
pp. 997-1001 ◽  
Author(s):  
Koichi Yokogawa ◽  
Masayuki Yonekawa ◽  
Ikumi Tamai ◽  
Rikiya Ohashi ◽  
Yasuaki Tatsumi ◽  
...  
Keyword(s):  
Transport Activity ◽  
Wild Type ◽  
Carnitine Transport

scholarly journals T Helper Type 17 Immune Response Plays an Indispensable Role for Development of Iodine-Induced Autoimmune Thyroiditis in Nonobese Diabetic-H2h4 Mice

Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 5135-5142 ◽  
Author(s):  
Ichiro Horie ◽  
Norio Abiru ◽  
Yuji Nagayama ◽  
Genpei Kuriya ◽  
Ohki Saitoh ◽  
...  
Keyword(s):  
Immune Response ◽  
Autoimmune Thyroiditis ◽  
Th17 Cells ◽  
Intermediate Phenotype ◽  
Lymphocyte Infiltration ◽  
Wild Type ◽  
T Helper ◽  
Nonobese Diabetic ◽  
Th2 Immune Response ◽  
Helper Type

T helper type 1(Th1)/Th2 paradigm has been expanded by discovery of a novel effector T cell (Teff) subset, Th17 cells, which produce a proinflammatory cytokine IL-17. Th17 cells have recently been shown to play a major role in numerous autoimmune diseases that had previously been thought to be Th1-dominant diseases. We here studied the significance of Th17 cells in iodine-induced autoimmune thyroiditis in nonobese diabetic-H2h4 mice, a mouse model of Hashimoto’s thyroiditis in humans, which spontaneously develop antithyroglobulin autoantibodies and intrathyroidal lymphocyte infiltration when supplied with iodine in the drinking water. We observed increased numbers of Th1 and Th17 cells in spleen and accumulation of both types of Teff in the thyroid glands of iodine-fed wild-type mice, indicating that Th17 cells as well as Th1 cells constitute thyroid lesions. Furthermore, the incidence and severity of intrathyroidal lymphocyte infiltration, and the titers of antithyroglobulin autoantibodies were markedly reduced in iodine-treated IL-17−/− mice as compared with wild-type mice. Of interest, IL-17+/− mice showed an intermediate phenotype. Therefore, the present study, together with a previous report demonstrating the importance of Th1, not Th2, immune response for developing thyroiditis using mice deficient for interferon-γ or IL-4, clearly indicates that both Th1 and Th17 cells are critical Teff subsets for the pathogenesis of spontaneous autoimmune thyroiditis in nonobese diabetic-H2h4 mice.

scholarly journals Replacement of both tryptophan residues at 388 and 412 completely abolished cytochalasin B photolabelling of the GLUT1 glucose transporter

1994 ◽  
Vol 302 (2) ◽  
pp. 355-361 ◽  
Author(s):  
K Inukai ◽  
T Asano ◽  
H Katagiri ◽  
M Anai ◽  
M Funaki ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Cytochalasin B ◽  
Transmembrane Domain ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Site Directed Mutagenesis ◽  
Transport Activity ◽  
Wild Type ◽  
In The Wild ◽  
Glut1 Glucose Transporter

A mutated GLUT1 glucose transporter, a Trp-388, 412 mutant whose tryptophans 388 and 412 were both replaced by leucines, was constructed by site-directed mutagenesis and expressed in Chinese hamster ovary cells. Glucose transport activity was decreased to approx. 30% in the Trp-388, 412 mutant compared with that in the wild type, a similar decrease in transport activity had been observed previously in the Trp-388 mutant and the Trp-412 mutant which had leucine at 388 and 412 respectively. Cytochalasin B labelling of the Trp-388 mutant was only decreased rather than abolished, a result similar to that obtained previously for the Trp-412 mutant. Cytochalasin B labelling was finally abolished completely in the Trp-388, 412 mutant, while cytochalasin B binding to this mutant was decreased to approx. 30% of that of the wild-type GLUT1 at the concentration used for photolabelling. This level of binding is thought to be adequate to detect labelling, assuming that the labelling efficiency of these transporters is similar. These findings suggest that cytochalasin B binds to the transmembrane domain of the glucose transporter in the vicinity of helix 10-11, and is inserted covalently by photoactivation at either the 388 or the 412 site.

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