Subject: Basic medicine
Subject: Health sciences
Year: 2006
Type: Article
Type: PeerReviewed
Title: Inhibition of protein tyrosine phosphatase 1B by reactive oxygen species leads to maintenance of Ca2+ influx following store depletion in HEK 293 cells
Author: Bogeski, Ivan
Author: Bozem, Monika
Author: Sternfeld, Lutz
Author: Hofer, Hans Werner
Author: Schulz, Irene
Abstract: Depletion of inositol 1,4,5 trisphosphate-sensitive Ca2+ stores generates a yet unknown signal, which leads to increase in Ca2+ influx in different cell types [J.W. Putney Jr., A model for receptor-regulated calcium entry, Cell Calcium 7 (1986) 1–12]. Here, we describe a mechanism that modulates this store-operated Ca2+ entry (SOC). Ca2+ influx leads to inhibition of protein tyrosine phosphatase 1B (PTP1B) activity in HEK 293 cells [L. Sternfeld, et al., Tyrosine phosphatase PTP1B interacts with TRPV6 in vivo and plays a role in TRPV6-mediated calcium influx in HEK293 cells, Cell Signal 17 (2005) 951–960]. Since Ca2+ does not directly inhibit PTP1B, we assumed an intermediate signal, which links the rise in cytosolic Ca2+ concentration and PTP1B inhibition.We now show that Ca2+ influx is followed by generation of reactive oxygen species (ROS) and that it is reduced in cells preincubated with catalase. Furthermore, Ca2+-dependent inhibition of PTP1B can be abolished in the presence of catalase. H2O2 (100 M) directly added to cells inhibits PTP1B and leads to increase in Ca2+ influx after store depletion. PP1, an inhibitor of the Src family tyrosine kinases, prevents H2O2-induced Ca2+ influx. Our results show that ROS act as fine tuning modulators of Ca2+ entry. We assume that the Ca2+ influx channel or a protein involved in its regulation remains tyrosine phosphorylated as a consequence of PTP1B inhibition by ROS. This leads to maintained Ca2+ influx in the manner of a positive feedback loop.
Publisher:
Relation: https://eprints.ugd.edu.mk/2200/
Identifier: oai:eprints.ugd.edu.mk:2200
Identifier: https://eprints.ugd.edu.mk/2200/1/Cell%20Calcium%202006_PTP1B_Ca_H2O2.pdfIdentifier: Bogeski, Ivan and Bozem, Monika and Sternfeld, Lutz and Hofer, Hans Werner and Schulz, Irene (2006) Inhibition of protein tyrosine phosphatase 1B by reactive oxygen species leads to maintenance of Ca2+ influx following store depletion in HEK 293 cells. Cell Calcium, 40 (1). pp. 1-10. ISSN 01434160
Identifier: doi:10.1016/j.ceca.2006.03.003
