Redox Regulation of a Soybean Tyrosine-Specific Protein Phosphatase†

Biochemistry ◽  
2005 ◽  
Vol 44 (21) ◽  
pp. 7696-7703 ◽  
Author(s):  
David P. Dixon ◽  
Anthony P. Fordham-Skelton ◽  
Robert Edwards
2021 ◽  
Vol 7 (7) ◽  
pp. 540
Author(s):  
Ágnes Jakab ◽  
Tamás Emri ◽  
Kinga Csillag ◽  
Anita Szabó ◽  
Fruzsina Nagy ◽  
...  

The glucocorticoid betamethasone (BM) has potent anti-inflammatory and immunosuppressive effects; however, it increases the susceptibility of patients to superficial Candida infections. Previously we found that this disadvantageous side effect can be counteracted by menadione sodium bisulfite (MSB) induced oxidative stress treatment. The fungus specific protein phosphatase Z1 (CaPpz1) has a pivotal role in oxidative stress response of Candida albicans and was proposed as a potential antifungal drug target. The aim of this study was to investigate the combined effects of CaPPZ1 gene deletion and MSB treatment in BM pre-treated C. albicans cultures. We found that the combined treatment increased redox imbalance, enhanced the specific activities of antioxidant enzymes, and reduced the growth in cappz1 mutant (KO) strain. RNASeq data demonstrated that the presence of BM markedly elevated the number of differentially expressed genes in the MSB treated KO cultures. Accumulation of reactive oxygen species, increased iron content and fatty acid oxidation, as well as the inhibiting ergosterol biosynthesis and RNA metabolic processes explain, at least in part, the fungistatic effect caused by the combined stress exposure. We suggest that the synergism between MSB treatment and CaPpz1 inhibition could be considered in developing of a novel combinatorial antifungal strategy accompanying steroid therapy.


1993 ◽  
Vol 268 (9) ◽  
pp. 6505-6510
Author(s):  
P.J. Kennelly ◽  
K.A. Oxenrider ◽  
J. Leng ◽  
J.S. Cantwell ◽  
N. Zhao

2001 ◽  
Vol 396 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Alexandra V. Andreeva ◽  
Olga V. Solov'eva ◽  
Dmitry L. Kakuev ◽  
Mikhail A. Kutuzov

2000 ◽  
Vol 80 (1) ◽  
pp. 173-210 ◽  
Author(s):  
Stefan Herzig ◽  
Joachim Neumann

This review deals with the influence of serine/threonine-specific protein phosphatases on the function of ion channels in the plasma membrane of excitable tissues. Particular focus is given to developments of the past decade. Most of the electrophysiological experiments have been performed with protein phosphatase inhibitors. Therefore, a synopsis is required incorporating issues from biochemistry, pharmacology, and electrophysiology. First, we summarize the structural and biochemical properties of protein phosphatase (types 1, 2A, 2B, 2C, and 3–7) catalytic subunits and their regulatory subunits. Then the available pharmacological tools (protein inhibitors, nonprotein inhibitors, and activators) are introduced. The use of these inhibitors is discussed based on their biochemical selectivity and a number of methodological caveats. The next section reviews the effects of these tools on various classes of ion channels (i.e., voltage-gated Ca2+ and Na+ channels, various K+ channels, ligand-gated channels, and anion channels). We delineate in which cases a direct interaction between a protein phosphatase and a given channel has been proven and where a more complex regulation is likely involved. Finally, we present ideas for future research and possible pathophysiological implications.


2021 ◽  
Vol 14 (669) ◽  
pp. eabc6435
Author(s):  
Tai An ◽  
Huiqing Hu ◽  
Ziyin Li

Trypanosoma brucei, an important human parasite, has a flagellum that controls cell motility, morphogenesis, proliferation, and cell-cell communication. Inheritance of the newly assembled flagellum during the cell cycle requires the Polo-like kinase homolog TbPLK and the kinetoplastid-specific protein phosphatase KPP1, although whether TbPLK acts on KPP1 or vice versa has been unclear. Here, we showed that dephosphorylation of TbPLK on Thr125 by KPP1 maintained low TbPLK activity in the flagellum-associated hook complex structure, thereby ensuring proper flagellum positioning and attachment. This dephosphorylation event required the recognition of phosphorylated Thr198 in the activation loop of TbPLK by the N-terminal Plus3 domain of KPP1 and the dephosphorylation of phosphorylated Thr125 in TbPLK by the C-terminal catalytic domain of KPP1. Dephosphorylation of TbPLK by KPP1 prevented hyperphosphorylation of the hook complex protein TbCentrin2, thereby allowing timely dephosphorylation of phosphorylated TbCentrin2 for hook complex duplication and flagellum positioning and attachment. Thus, KPP1 attenuates TbPLK activity by dephosphorylating TbPLK to facilitate flagellum inheritance.


2019 ◽  
Vol 116 (16) ◽  
pp. 8028-8037 ◽  
Author(s):  
Sehoon Won ◽  
Salvatore Incontro ◽  
Yan Li ◽  
Roger A. Nicoll ◽  
Katherine W. Roche

Striatal-enriched protein tyrosine phosphatase (STEP) is a brain-specific protein phosphatase that regulates a variety of synaptic proteins, including NMDA receptors (NAMDRs). To better understand STEP’s effect on other receptors, we used mass spectrometry to identify the STEP61 interactome. We identified a number of known interactors, but also ones including the GluA2 subunit of AMPA receptors (AMPARs). We show that STEP61 binds to the C termini of GluA2 and GluA3 as well as endogenous AMPARs in hippocampus. The synaptic expression of GluA2 and GluA3 is increased in STEP-KO mouse brain, and STEP knockdown in hippocampal slices increases AMPAR-mediated synaptic currents. Interestingly, STEP61 overexpression reduces the synaptic expression and synaptic currents of both AMPARs and NMDARs. Furthermore, STEP61 regulation of synaptic AMPARs is mediated by lysosomal degradation. Thus, we report a comprehensive list of STEP61 binding partners, including AMPARs, and reveal a central role for STEP61 in differentially organizing synaptic AMPARs and NMDARs.


2020 ◽  
Vol 528 (3) ◽  
pp. 607-611
Author(s):  
George W. Templeton ◽  
Jayde J. Johnson ◽  
Nicolas A. Sieben ◽  
Greg B. Moorhead

1995 ◽  
Vol 21 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Thomas F. Jenny ◽  
Dietlind L. Gerloff ◽  
Mark A. Cohen ◽  
Steven A. Benner

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