Structural and biochemical characterization of Siw14: A protein-tyrosine phosphatase fold that metabolizes inositol pyrophosphates

Wang, Huanchen; Gu, Chunfang; Rolfes, Ronda J.; Jessen, Henning J.; Shears, Stephen B.

doi:10.1074/jbc.ra117.001670

Cited by 27 publications

(51 citation statements)

References 47 publications

(70 reference statements)

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“…It contains a C-terminal DSP domain (res. 117–281) enriched in basic amino acids (isoelectric point 9.0) (14) preceded by a very acidic NTD (res. 1–108, isoelectric point 4.4) (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…In vitro studies using recombinant Siw14 later clarified that Siw14 selectively hydrolyzes the β-phosphate at the 5-position on 5-diphosphoinositol pentakisphosphate (5-PP-IP5) (13). Siw14 is also active toward other PP-IPs such as 5-PP-IP4, 5-IP7 and 1,5-PP-IP4 (also known as IP8), but it has negligible activity against 1-IP7, which is present in very small quantities in yeast cells (14). Thus, the presence of a 5-β-phosphate is an essential determinant for Siw14 catalytic specificity.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Architecture of the Inositol Phosphatase Siw14

et al. 2018

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Siw14 is a recently discovered inositol phosphatase implicated in suppressing prion propagation in Saccharomyces cerevisiae. In this paper, we used hybrid structural methods to decipher Siw14 molecular architecture. We found the protein exists in solution as an elongate monomer ~140 Å in length, containing an acidic N-terminal domain (NTD) and a basic C-terminal dual specificity phosphatase (DSP) domain, structurally similar to the glycogen phosphatase laforin. The two domains are connected by a protease susceptible linker and do not interact in vitro. The crystal structure of Siw14-DSP reveals a highly basic phosphate-binding loop and a ~10 Å deep substrate-binding crevice evolved to dephosphorylate pyro-phosphate moieties. A pseudo-atomic model of the full-length phosphatase generated from solution, crystallographic, biochemical and modeling data sheds light on the interesting zwitterionic nature of Siw14, which we hypothesized may play a role in discriminating negatively charged inositol phosphates.

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“…It contains a C-terminal DSP domain (res. 117–281) enriched in basic amino acids (isoelectric point 9.0) (14) preceded by a very acidic NTD (res. 1–108, isoelectric point 4.4) (Fig.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Architecture of the Inositol Phosphatase Siw14

et al. 2018

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“…Siw14, Had1, and Oca1/101 could also be good targets for cryptococcal treatment because there are no evident orthologues of these phosphatases in humans. Recently, the structure of the S. cerevisiae inositol phosphatase Siw14 has also been resolved 91 , whereas structural information for Had1 and Oca1/Oca101 is not yet available.…”

Section: Discussionmentioning

confidence: 99%

Genome-wide functional analysis of phosphatases in the pathogenic fungus Cryptococcus neoformans

et al. 2020

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Phosphatases, together with kinases and transcription factors, are key components in cellular signalling networks. Here, we present a systematic functional analysis of the phosphatases in Cryptococcus neoformans , a fungal pathogen that causes life-threatening fungal meningoencephalitis. We analyse 230 signature-tagged mutant strains for 114 putative phosphatases under 30 distinct in vitro growth conditions, revealing at least one function for 60 of these proteins. Large-scale virulence and infectivity assays using insect and mouse models indicate roles in pathogenicity for 31 phosphatases involved in various processes such as thermotolerance, melanin and capsule production, stress responses, O- mannosylation, or retromer function. Notably, phosphatases Xpp1, Ssu72, Siw14, and Sit4 promote blood-brain barrier adhesion and crossing by C. neoformans . Together with our previous systematic studies of transcription factors and kinases, our results provide comprehensive insight into the pathobiological signalling circuitry of C. neoformans .

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“…Siw14 belongs to the atypical dual-specificity phosphatase family and hydrolyzes the ß-phosphate of 5-InsP 7 with high specificity ( Steidle et al, 2016 ; Wang et al, 2018 ). Mutants lacking SIW14 display a sixfold increase in InsP 7 content.…”

Section: Elements Of the Inphors Pathwaymentioning

confidence: 99%

Phosphate Homeostasis − A Vital Metabolic Equilibrium Maintained Through the INPHORS Signaling Pathway

Austin

Mayer

2020

Front. Microbiol.

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Cells face major changes in demand for and supply of inorganic phosphate (P i ). P i is often a limiting nutrient in the environment, particularly for plants and microorganisms. At the same time, the need for phosphate varies, establishing conflicts of goals. Cells experience strong peaks of P i demand, e.g., during the S-phase, when DNA, a highly abundant and phosphate-rich compound, is duplicated. While cells must satisfy these P i demands, they must safeguard themselves against an excess of P i in the cytosol. This is necessary because P i is a product of all nucleotide-hydrolyzing reactions. An accumulation of P i shifts the equilibria of these reactions and reduces the free energy that they can provide to drive endergonic metabolic reactions. Thus, while P i starvation may simply retard growth and division, an elevated cytosolic P i concentration is potentially dangerous for cells because it might stall metabolism. Accordingly, the consequences of perturbed cellular P i homeostasis are severe. In eukaryotes, they range from lethality in microorganisms such as yeast ( Sethuraman et al., 2001 ; Hürlimann, 2009 ), severe growth retardation and dwarfism in plants ( Puga et al., 2014 ; Liu et al., 2015 ; Wild et al., 2016 ) to neurodegeneration or renal Fanconi syndrome in humans ( Legati et al., 2015 ; Ansermet et al., 2017 ). Intracellular P i homeostasis is thus not only a fundamental topic of cell biology but also of growing interest for medicine and agriculture.

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Structural and biochemical characterization of Siw14: A protein-tyrosine phosphatase fold that metabolizes inositol pyrophosphates

Cited by 27 publications

References 47 publications

Molecular Architecture of the Inositol Phosphatase Siw14

Molecular Architecture of the Inositol Phosphatase Siw14

Genome-wide functional analysis of phosphatases in the pathogenic fungus Cryptococcus neoformans

Phosphate Homeostasis − A Vital Metabolic Equilibrium Maintained Through the INPHORS Signaling Pathway

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