Acid-sensing ion channel 1 (ASIC1) is a H(+)-gated channel of the amiloride-sensitive epithelial Na(+) channel (ENaC)/degenerin family. ASIC1 is expressed mostly in the central and peripheral nervous system neurons. ENaC and ASIC function is regulated by several serine proteases. The type II transmembrane serine protease matriptase activates the prototypical alphabetagammaENaC channel, but we found that matriptase is expressed in glioma cells and its expression is higher in glioma compared with normal astrocytes. Therefore, the goal of this study was to test the hypothesis that matriptase regulates ASIC1 function. Matriptase decreased the acid-activated ASIC1 current as measured by two-electrode voltage clamp in Xenopus oocytes and cleaved ASIC1 expressed in oocytes or CHO K1 cells. Inactive S805A matriptase had no effect on either the current or the cleavage of ASIC1. The effect of matriptase on ASIC1 was specific, because it did not affect the function of ASIC2 and no matriptase-specific ASIC2 fragments were detected in oocytes or in CHO cells. Three matriptase recognition sites were identified in ASIC1 (Arg-145, Lys-185, and Lys-384). Site-directed mutagenesis of these sites prevented matriptase cleavage of ASIC1. Our results show that matriptase is expressed in glioma cells and that matriptase specifically cleaves ASIC1 in heterologous expression systems.
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http://dx.doi.org/10.1074/jbc.M110.153213 | DOI Listing |
Turk J Pediatr
November 2024
Department of Pediatric Hematology, Faculty of Medicine, Hacettepe University, Ankara, Türkiye.
Background: Iron refractory iron deficiency anemia (IRIDA) is a rare autosomal recessive type of anemia characterized by unresponsiveness to oral iron therapy and partial response to parenteral iron therapy. In this article, we report the clinical presentation of four patients with IRIDA admitted to our clinic, including their laboratory values at admission and after oral and parenteral iron treatment, and the analysis of their mutation(s) in TMPRSS6 gene.
Case: Four patients from different families, aged between 3 and 14 years, two girls and two boys, two of whom were from consanguineous marriages, who were diagnosed with iron deficiency anemia in primary health care institutions and referred to our clinic because of inadequate response to oral iron treatment were included.
Matrix Biol
December 2024
Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland. Electronic address:
The extracellular matrix (ECM) serves as a physical scaffold for tissues that is composed of structural proteins such as laminins, collagens, proteoglycans and fibronectin, forming a three dimensional network, and a wide variety of other matrix proteins with ECM-remodeling and signaling functions. The activity of ECM-associated signaling proteins is tightly regulated. Thus, the ECM serves as a reservoir for water and growth regulatory signals.
View Article and Find Full Text PDFCell Death Dis
October 2024
Institute of Zoology / Developmental Biology, University of Cologne, Cologne, Germany.
Evasion of cell death is a hallmark of cancer, and consequently the induction of cell death is a common strategy in cancer treatment. However, the molecular mechanisms regulating different types of cell death are poorly understood. We have formerly shown that in the epidermis of hypomorphic zebrafish hai1a mutant embryos, pre-neoplastic transformations of keratinocytes caused by unrestrained activity of the type II transmembrane serine protease Matriptase-1 heal spontaneously.
View Article and Find Full Text PDFProtein Sci
August 2024
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, USA.
Sci Rep
July 2024
Department of Pharmacology and Toxicology, University of Veterinary Medicine, István Utca 2, 1078, Budapest, Hungary.
Certain corona- and influenza viruses utilize type II transmembrane serine proteases for cell entry, making these enzymes potential drug targets for the treatment of viral respiratory infections. In this study, the cytotoxicity and inhibitory effects of seven matriptase/TMPRSS2 inhibitors (MI-21, MI-463, MI-472, MI-485, MI-1900, MI-1903, and MI-1904) on cytochrome P450 enzymes were evaluated using fluorometric assays. Additionally, their antiviral activity against influenza A virus subtypes H1N1 and H9N2 was assessed.
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