Title
Characterization of a novel serine/threonine protein phosphatase (PfPPJ) from the malaria parasite, Plasmodium falciparum
Abbreviated Journal Title
Mol. Biochem. Parasitol.
Keywords
protein phosphatase; Plasmodium falciparum; okadaic acid; stage-specific; expression; SER-THR PHOSPHATASES; MUTATIONAL ANALYSIS; CATALYTIC SUBUNIT; DEVELOPMENTAL REGULATION; EXPRESSION; INHIBITION; IDENTIFICATION; CALCINEURIN; PHOSPHORYLATION; LOCALIZATION; Biochemistry & Molecular Biology; Parasitology
Abstract
A novel protein phosphatase cDNA of the PPP superfamily was identified from the malaria parasite, Plasmodium falciparum (Pf), and tentatively named PfPPJ. The predicted primary structure of the phosphatase contained all the known conserved motifs of the PPP superfamily essential for catalytic activity. The enzyme was specific for dephosphorylation of phosphoserine and phosphothreonine residues with very little activity against phosphotyrosine residues. However, the sequence at its C-terminal end was unique, and was consistent with its resistance to the classical PP2A-specific inhibitors such as okadaic acid and microcystin-LR, and the PPI-specific inhibitor, mammalian heat-stable inhibitor-2 (I-2). Even the catalytic core of PfPPJ had a sequence substantially different from the other PPPs such that PfPPJ could be placed in an apparently separate phylogenetic branch. At 294 amino acids residues, PfPPJ was one of the smallest okadaic acid-resistant PPP phosphatases known. By Northern blot analysis, the expression of the PfPPJ mRNA showed the following pattern: schizont > ring > trophozoite, which closely paralleled the expression of the protein, as determined by immunofluorescence. Together, these results suggested a parasitic stage-specific transcriptional regulation of this novel and potentially unique protozoan phosphatase. (C) 2001 Elsevier Science B.V. All rights reserved.
Journal Title
Molecular and Biochemical Parasitology
Volume
115
Issue/Number
1
Publication Date
1-1-2001
Document Type
Article; Proceedings Paper
Language
English
First Page
29
Last Page
39
WOS Identifier
ISSN
0166-6851
Recommended Citation
"Characterization of a novel serine/threonine protein phosphatase (PfPPJ) from the malaria parasite, Plasmodium falciparum" (2001). Faculty Bibliography 2000s. 7972.
https://stars.library.ucf.edu/facultybib2000/7972
Comments
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