Difference between revisions of "Phosphatase Superfamily PHP"

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[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Fold_PHP|PHP Fold]]: [[Phosphatase_Superfamily_PHP|PHP Superfamily]]
  
[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Superfamily_PHP|PHP Superfamily]]
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PHP is the only phosphatase known to be histidine-specific.
  
PHP is the only known protein Histidine phosphate, and consists of a single family, also known as [[Phosphatase_Family_PHP|PHP]].
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=== Evolution ===
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PHP is found throughout eukaryotes, though lost from fungi. It is usually single copy per genome, but four are found in fruit fly.
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=== Domain ===
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PHP has a single domain: catalytic domain. The structure of the domain has been solved and a potential enzymatic mechanism proposed <cite>Gong</cite>.
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=== Functions ===
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Several substrates have been reported, including ''beta'' subunit of heterotrimeric G proteins <cite>Maurer04</cite>, the metabolic enzyme adenosine 5’-triphosphate-citrate lyase (ACL) <cite>Klumpp03</cite>, and the Ca2+-activated K+ channel KCa3.1 <cite>Skolnik08</cite>. These are known or suspected substrates of the nucleoside diphosphate kinases ([http://kinase.com/wiki/index.php/Kinase_Group_NDK NDK]).
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Its role in neuronal cells is particularly interesting. In ''C. elegans'', the ortholog is expressed exclusively in neurons <cite>Klumpp02</cite>. In human cells, the overexpression of PHPT1 decreases the activity of adenosine 5’-triphosphate-citrate lyase (ACL) and reduces the viability of neuronal cells <cite>Klumpp09</cite>.
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=== References ===
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<biblio>
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#Gong pmid=18991813
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#Maurer04 pmid=16039992
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#Klumpp03 pmid=12788074
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#Skolnik08 pmid=18796614
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#Klumpp02 pmid=12468887
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#Klumpp09 pmid=19138678
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</biblio>

Revision as of 17:44, 1 January 2015

Phosphatase Classification: PHP Fold: PHP Superfamily

PHP is the only phosphatase known to be histidine-specific.

Evolution

PHP is found throughout eukaryotes, though lost from fungi. It is usually single copy per genome, but four are found in fruit fly.

Domain

PHP has a single domain: catalytic domain. The structure of the domain has been solved and a potential enzymatic mechanism proposed [1].

Functions

Several substrates have been reported, including beta subunit of heterotrimeric G proteins [2], the metabolic enzyme adenosine 5’-triphosphate-citrate lyase (ACL) [3], and the Ca2+-activated K+ channel KCa3.1 [4]. These are known or suspected substrates of the nucleoside diphosphate kinases (NDK).

Its role in neuronal cells is particularly interesting. In C. elegans, the ortholog is expressed exclusively in neurons [5]. In human cells, the overexpression of PHPT1 decreases the activity of adenosine 5’-triphosphate-citrate lyase (ACL) and reduces the viability of neuronal cells [6].


References

  1. Gong W, Li Y, Cui G, Hu J, Fang H, Jin C, and Xia B. Solution structure and catalytic mechanism of human protein histidine phosphatase 1. Biochem J. 2009 Mar 1;418(2):337-44. DOI:10.1042/BJ20081571 | PubMed ID:18991813 | HubMed [Gong]
  2. Mäurer A, Wieland T, Meissl F, Niroomand F, Mehringer R, Krieglstein J, and Klumpp S. The beta-subunit of G proteins is a substrate of protein histidine phosphatase. Biochem Biophys Res Commun. 2005 Sep 9;334(4):1115-20. DOI:10.1016/j.bbrc.2005.06.200 | PubMed ID:16039992 | HubMed [Maurer04]
  3. Klumpp S, Bechmann G, Mäurer A, Selke D, and Krieglstein J. ATP-citrate lyase as a substrate of protein histidine phosphatase in vertebrates. Biochem Biophys Res Commun. 2003 Jun 20;306(1):110-5. DOI:10.1016/s0006-291x(03)00920-3 | PubMed ID:12788074 | HubMed [Klumpp03]
  4. Srivastava S, Zhdanova O, Di L, Li Z, Albaqumi M, Wulff H, and Skolnik EY. Protein histidine phosphatase 1 negatively regulates CD4 T cells by inhibiting the K+ channel KCa3.1. Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14442-6. DOI:10.1073/pnas.0803678105 | PubMed ID:18796614 | HubMed [Skolnik08]
  5. Klumpp S, Hermesmeier J, Selke D, Baumeister R, Kellner R, and Krieglstein J. Protein histidine phosphatase: a novel enzyme with potency for neuronal signaling. J Cereb Blood Flow Metab. 2002 Dec;22(12):1420-4. DOI:10.1097/01.wcb.0000045041.03034.99 | PubMed ID:12468887 | HubMed [Klumpp02]
  6. Klumpp S, Faber D, Fischer D, Litterscheid S, and Krieglstein J. Role of protein histidine phosphatase for viability of neuronal cells. Brain Res. 2009 Apr 6;1264:7-12. DOI:10.1016/j.brainres.2008.12.052 | PubMed ID:19138678 | HubMed [Klumpp09]
All Medline abstracts: PubMed | HubMed