Cargando…

A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis

BACKGROUND: Phosphoinositide metabolism is essential to membrane dynamics and impinges on many cellular processes, including phagocytosis. Modulation of phosphoinositide metabolism is important for pathogenicity and virulence of many human pathogens, allowing them to survive and replicate in the hos...

Descripción completa

Detalles Bibliográficos
Autores principales: Beresford, Nicola J, Saville, Charis, Bennett, Hayley J, Roberts, Ian S, Tabernero, Lydia
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3091653/
https://www.ncbi.nlm.nih.gov/pubmed/20678187
http://dx.doi.org/10.1186/1471-2164-11-457
_version_ 1782203296203669504
author Beresford, Nicola J
Saville, Charis
Bennett, Hayley J
Roberts, Ian S
Tabernero, Lydia
author_facet Beresford, Nicola J
Saville, Charis
Bennett, Hayley J
Roberts, Ian S
Tabernero, Lydia
author_sort Beresford, Nicola J
collection PubMed
description BACKGROUND: Phosphoinositide metabolism is essential to membrane dynamics and impinges on many cellular processes, including phagocytosis. Modulation of phosphoinositide metabolism is important for pathogenicity and virulence of many human pathogens, allowing them to survive and replicate in the host cells. Phosphoinositide phosphatases from bacterial pathogens are therefore key players in this modulation and constitute attractive targets for chemotherapy. MptpB, a virulence factor from Mycobacterium tuberculosis, has phosphoinositide phosphatase activity and a distinct active site P-loop signature HCXXGKDR that shares characteristics with eukaryotic lipid phosphatases and protein tyrosine phosphatases. We used this P-loop signature as a "diagnostic motif" to identify related putative phosphatases with phosphoinositide activity in other organisms. RESULTS: We found more than 200 uncharacterised putative phosphatase sequences with the conserved signature in bacteria, with some related examples in fungi and protozoa. Many of the sequences identified belong to recognised human pathogens. Interestingly, no homologues were found in any other organisms including Archaea, plants, or animals. Phylogenetic analysis revealed that these proteins are unrelated to classic eukaryotic lipid phosphatases. However, biochemical characterisation of those from Listeria monocytogenes and Leishmania major, demonstrated that, like MptpB, they have phosphatase activity towards phosphoinositides. Mutagenesis studies established that the conserved Asp and Lys in the P-loop signature (HCXXGKDR) are important in catalysis and substrate binding respectively. Furthermore, we provide experimental evidence that the number of basic residues in the P-loop is critical in determining activity towards poly-phosphoinositides. CONCLUSION: This new family of enzymes in microorganisms shows distinct sequence and biochemical characteristics to classic eukaryotic lipid phosphatases and they have no homologues in humans. This study provides a foundation for examining the biological role of this new family of phosphatases and their potential as pharmaceutical targets against infectious diseases.
format Text
id pubmed-3091653
institution National Center for Biotechnology Information
language English
publishDate 2010
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-30916532011-05-11 A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis Beresford, Nicola J Saville, Charis Bennett, Hayley J Roberts, Ian S Tabernero, Lydia BMC Genomics Research Article BACKGROUND: Phosphoinositide metabolism is essential to membrane dynamics and impinges on many cellular processes, including phagocytosis. Modulation of phosphoinositide metabolism is important for pathogenicity and virulence of many human pathogens, allowing them to survive and replicate in the host cells. Phosphoinositide phosphatases from bacterial pathogens are therefore key players in this modulation and constitute attractive targets for chemotherapy. MptpB, a virulence factor from Mycobacterium tuberculosis, has phosphoinositide phosphatase activity and a distinct active site P-loop signature HCXXGKDR that shares characteristics with eukaryotic lipid phosphatases and protein tyrosine phosphatases. We used this P-loop signature as a "diagnostic motif" to identify related putative phosphatases with phosphoinositide activity in other organisms. RESULTS: We found more than 200 uncharacterised putative phosphatase sequences with the conserved signature in bacteria, with some related examples in fungi and protozoa. Many of the sequences identified belong to recognised human pathogens. Interestingly, no homologues were found in any other organisms including Archaea, plants, or animals. Phylogenetic analysis revealed that these proteins are unrelated to classic eukaryotic lipid phosphatases. However, biochemical characterisation of those from Listeria monocytogenes and Leishmania major, demonstrated that, like MptpB, they have phosphatase activity towards phosphoinositides. Mutagenesis studies established that the conserved Asp and Lys in the P-loop signature (HCXXGKDR) are important in catalysis and substrate binding respectively. Furthermore, we provide experimental evidence that the number of basic residues in the P-loop is critical in determining activity towards poly-phosphoinositides. CONCLUSION: This new family of enzymes in microorganisms shows distinct sequence and biochemical characteristics to classic eukaryotic lipid phosphatases and they have no homologues in humans. This study provides a foundation for examining the biological role of this new family of phosphatases and their potential as pharmaceutical targets against infectious diseases. BioMed Central 2010-08-02 /pmc/articles/PMC3091653/ /pubmed/20678187 http://dx.doi.org/10.1186/1471-2164-11-457 Text en Copyright ©2010 Beresford et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Beresford, Nicola J
Saville, Charis
Bennett, Hayley J
Roberts, Ian S
Tabernero, Lydia
A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title_full A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title_fullStr A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title_full_unstemmed A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title_short A new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
title_sort new family of phosphoinositide phosphatases in microorganisms: identification and biochemical analysis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3091653/
https://www.ncbi.nlm.nih.gov/pubmed/20678187
http://dx.doi.org/10.1186/1471-2164-11-457
work_keys_str_mv AT beresfordnicolaj anewfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT savillecharis anewfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT bennetthayleyj anewfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT robertsians anewfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT tabernerolydia anewfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT beresfordnicolaj newfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT savillecharis newfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT bennetthayleyj newfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT robertsians newfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis
AT tabernerolydia newfamilyofphosphoinositidephosphatasesinmicroorganismsidentificationandbiochemicalanalysis