14-kDa Phosphohistidine phosphatase plays an important role in hepatocellular carcinoma cell proliferation

Han, Suxia; Wang, Lijuan; Zhao, Jing; Zhang, Ying; Li, Meng; Zhou, Xia; Wang, Jing; Zhu, Qing

doi:10.3892/ol.2012.802

Cited by 16 publications

(13 citation statements)

References 27 publications

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“…The identities of the pHis proteins we identified suggest that pHis may play a role in mammalian cell signaling [32][33][34] . Indeed, a direct correlation of pHis protein levels with carcinogenesis has recently been reported 30,[35][36][37] . Interestingly, we identified 20 N-phosphate sites on proteins that were reported to be enriched by IAP by Hindupur et al from mTOR-driven hepatocellular carcinoma mouse tumors as potential LHPP substrates, including BCLAF1, which in our studies was found to contain pLys (K391) with a reasonable probability of localization of 79.6%.…”

Section: Discussionmentioning

confidence: 95%

A non-acidic method using hydroxyapatite and phosphohistidine monoclonal antibodies allows enrichment of phosphopeptides containing non-conventional phosphorylations for mass spectrometry analysis

Adam

Fuhs

Meisenhelder

et al. 2019

Preprint

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Four types of phosphate-protein linkage generate nine different phosphoresidues in living organisms. Histidine phosphorylation is a long-time established but largely unexplored post-translational modification, mainly because of the acid-lability of the phosphoramidate bonds. This lability means that standard phosphoproteomic methods used for conventional phosphate esters (phospho-Ser/Thr/Tyr) must be modified to analyze proteins containing the phosphoramidate-amino acids -phospho-His/Arg/Lys. We show that a non-acidic method allows enrichment of non-conventional phosphoresiduecontaining peptides from tryptic digests of human cell lines, using hydroxyapatite binding and/or immobilized 1-pHis and 3-pHis monoclonal antibodies for enrichment. 425 unique non-conventional phosphorylation sites (i.e. pHis, pLys and pArg) were detected with a high probability of localization by LC-MS/MS analysis and identified using a customized MaxQuant configuration, contributing to a new era of study in post-translational modification and cell signaling in humans. This is the first fully non-acidic method for phosphopeptide enrichment which uses immunoaffinity purification and remains compatible with mass spectrometry analysis for a wider coverage of potential protein phosphorylation events. Introduction:Phosphoproteomics has contributed to tremendous progress in the field of life science and revealed the extensive use of phosphorylation as one of the most important post-translational modifications in eukaryotic organisms. The identification and characterization of phosphorylation sites has been revolutionized by mass spectrometry (MS) with faster and more sensitive instruments. Progress in phosphosite-mapping with tandem mass spectrometry (MS/MS) has allowed improved localization and phosphorylation assignment to a single residue with high confidence. The development of bioinformatics tools for large-scale phosphoproteome data analysis was an equally important step and permitted the integration of different parameters searching for complex combinatorial possibilities 1,2 .Up until now, only one class of phosphate-bond containing phosphoamino acid, corresponding to the conventional serine, threonine and tyrosine phosphorylation (phosphate-ester or O-phosphate) has been systematically considered for phosphorylation site searching. But nine out of the 20 amino acids have the

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Section: Discussionmentioning

confidence: 95%

A non-acidic method using hydroxyapatite and phosphohistidine monoclonal antibodies allows enrichment of phosphopeptides containing non-conventional phosphorylations for mass spectrometry analysis

Adam

Fuhs

Meisenhelder

et al. 2019

Preprint

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“…[45] The intermediate conductance Ca 2 + -activated K + channel (SK4) [46] and transientr eceptor potentialc hannel 4 (TRPC4) have also been proposed as in vivo targets of PHPT1; [47] thus implicating the role of PHPT1 in vasculoproliferative diseases and insulin secretion. Severals tudies indicated that higherl evels of PHPT1 expression were associated with lung, [48,49] renal, [50] and liver [51] cancers. PHPT1 knockdown in these cancer cells inhibited cell proliferation, which supported the potential therapeutic values of PHPT1-specific inhibitors.…”

Section: Phpt1mentioning

confidence: 99%

Recent Updates on Protein N‐Phosphoramidate Hydrolases

2018

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In contrast to well‐recognized protein phosphorylation on the side‐chain oxygen of Ser, Thr, or Tyr residues, analogous phosphoramidation of the nitrogen of His, Lys, and Arg side chains remains much less investigated, mainly due to the instability of post‐translational modifications and technical difficulties involved in their analysis. For example, reports on the enzyme activities responsible for the formation and hydrolysis of these phosphoramidates date back to as early as the 1950s, but some of these enzymes have only recently been identified and functionally characterized; this has been aided by the development of novel research tools. In this review, we summarize current knowledge of the enzymes that hydrolyze protein N‐phosphoramidates, in terms of their structure, activities, and biological functions, as well as the chemical tools used to investigate them.

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“…The interesting possibility of NDPK acting as a protein kinase with PHPT1 as the balancing phosphoprotein phosphatase has been discussed in a review by Wieland et al ( 30 ). Furthermore, evidence for a possible role of PHPT1 in cytoskeletal reorganization ( 31,32 ) and in hepatocellular carcinoma cell proliferation ( 33 ) has been presented. In several of the experiments above, the possibilities to modulate the expression of the PHPT1 gene have been crucial.…”

Section: Introductionmentioning

confidence: 99%

Phosphohistidine phosphatase 1 (PHPT1) also dephosphorylates phospholysine of chemically phosphorylated histone H1 and polylysine

Zetterqvist

2015

Upsala Journal of Medical Sciences

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Background Phosphohistidine phosphatase 1 (PHPT1), also named protein histidine phosphatase (PHP), is a eukaryotic enzyme dephosphorylating proteins and peptides that are phosphorylated on a histidine residue. A preliminary finding that histone H1, which lacks histidine, was phosphorylated by phosphoramidate and dephosphorylated by PHPT1 prompted the present investigation.Methods Histone H1 and polylysine were phosphorylated at a low concentration (3.9 mM) of phosphoramidate. Their dephosphorylation by recombinant human PHPT1 was investigated by using a DEAE-Sepharose spin column technique earlier developed by us for studies on basic phosphoproteins and phosphopeptides. Determination of protein-bound, acid-labile phosphate was performed by a malachite green method. Mass spectrometry (MS) was used to investigate the occurrence of N-ε-phospholysine residues in a phosphorylated histone H1.2 preparation, and to measure the activity of PHPT1 against free N-ω-phosphoarginine.Results Histone H1.2, which lacks histidine, was phosphorylated by phosphoramidate on several lysine residues, as shown by MS. PHPT1 was shown to dephosphorylate phosphohistone H1 at a rate similar to that previously described for the dephosphorylation of phosphohistidine-containing peptides. In addition, phosphopolylysine was an equally good substrate for PHPT1. However, no dephosphorylation of free phosphoarginine by PHPT1 could be detected.Conclusion The finding that PHPT1 can dephosphorylate phospholysine in chemically phosphorylated histone H1 and polylysine demonstrates a broader specificity for this enzyme than known so far.

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14-kDa Phosphohistidine phosphatase plays an important role in hepatocellular carcinoma cell proliferation

Cited by 16 publications

References 27 publications

A non-acidic method using hydroxyapatite and phosphohistidine monoclonal antibodies allows enrichment of phosphopeptides containing non-conventional phosphorylations for mass spectrometry analysis

A non-acidic method using hydroxyapatite and phosphohistidine monoclonal antibodies allows enrichment of phosphopeptides containing non-conventional phosphorylations for mass spectrometry analysis

Recent Updates on Protein N‐Phosphoramidate Hydrolases

Phosphohistidine phosphatase 1 (PHPT1) also dephosphorylates phospholysine of chemically phosphorylated histone H1 and polylysine

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