Immunohistochemical localization of phosphohistidine phosphatase PHPT1 in mouse and human tissues - PubMed (original) (raw)

Immunohistochemical localization of phosphohistidine phosphatase PHPT1 in mouse and human tissues

Xiau-Qun Zhang et al. Ups J Med Sci. 2009.

Abstract

Protein histidine phosphorylation accounts for about 6% of the total protein phosphorylation in eukaryotic cells; still details concerning histidine phosphorylation and dephosphorylation are limited. A mammalian 14-kDa phosphohistidine phosphatase, also denominated PHPT1, was found 6 years ago that provided a new tool in the study of phosphohistidine phosphorylation. The localization of PHPT1 mRNA by Northern blot analysis revealed high expression in heart and skeletal muscle. The main object of the present study was to determine the PHPT1 expression on protein level in mouse tissues in order to get further information on the physiological role of the enzyme. Tissue samples from adult mice and 14.5-day-old mouse embryos were processed for immunostaining using a PHPT1-specific polyclonal antibody. The same antibody was also provided to the Swedish human protein atlas project (HPR) (http://www.proteinatlas.org/index.php). The results from both studies were essentially consistent with the previously reported expression of mRNA of a few human tissues. In addition, several other tissues, including testis, displayed a high protein expression. A salient result of the present investigation was the ubiquitous expression of the PHPT1 protein and its high expression in continuously dividing epithelial cells.

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Figures

Figure 1.

Figure 1.

Immunohistochemical staining for PHPT1. A: An E14.5 mouse embryo sagittal section shows PHPT1 signal in the epithelium of the choroid plexus in the fourth ventricle of brain (arrow). B: Adjacent section of A, using preimmune serum as a negative control. C: The same expression pattern of PHPT1 was found in the epithelium layer of the choroid plexus in an adult mouse brain (arrow). Arrowheads point at the ependymal cells in the ventricle. D: Purkinje cell (arrow) in the cerebellum expressing PHPT1. E: PHPT1 expression in the E14.5 embryonic heart muscle. F: PHPT1 expression (arrow) in the epithelium layer of the developing gut of an E14.5 sagittal section. Amplifications were 100× for A, B, and E, 400× for C and D, and 25× for F.

Figure 2.

Figure 2.

Immunohistochemical staining for PHPT1. A: A section of adult mouse kidney shows PHPT1 expression in the distal convoluted tubules (arrowhead) but not in the glomeruli (arrow) and a weak expression in the proximal convoluted tubule. B: PHPT1 is expressed in the Henle's loops of adult kidney. C and D: Sections of seminiferous tubule of adult mouse testis. Arrows in C point to the spermatogonium of seminiferous tubule. D: An absorption test shows that PHPT1 signals were abolished in the mouse testis. E: PHPT1 is expressed in the epithelium of interlobular duct of pancreas (arrow). F: PHPT1 is expressed in the epithelium of bronchiole (arrow). Arrowheads point at macrophages in alveoli. Amplifications were 400× for A–F.

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References

    1. Cohen P. The role of protein phosphorylation in human health and disease. The Sir Hans Krebs Medal Lecture. Eur J Biochem. 2001;268:5001–10. - PubMed
    1. Hunter T. Signalling—2000 and beyond. Cell. 2000;100:113–27. - PubMed
    1. Boyer PD, DeLuca M, Ebner KE, Hultquist DE, Peter JB. Identification of phosphohistidine in digests from a probable intermediate of oxidative phosphorylation. J Biol Chem. 1962;237:3306–8. - PubMed
    1. Matthews HR. Protein kinases and phosphatases that act on histidine, lysine, or arginine residues in eukaryotic proteins: a possible regulator of the mitogen-activated protein kinase cascade. Pharmacol Ther. 1995;67:323–50. - PubMed
    1. Besant PG, Attwood PV. Mammalian histidine kinases. Biochim Biophys Acta. 2005;1754:281–90. - PubMed

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