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Wu Y, Cruz LN, Szestak T, Laing G, Molyneux GR, Garcia CRS, Craig AG. An external sensing system in Plasmodium falciparum-infected erythrocytes. Malar J 2016; 15:103. [PMID: 26893139 PMCID: PMC4759932 DOI: 10.1186/s12936-016-1144-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/04/2016] [Indexed: 11/17/2022] Open
Abstract
Background A number of experiments have previously indicated that Plasmodium falciparum-infected erythrocytes (pRBC) were able to sense host environment. The basis of this ability to detect external cues is not known but in screening signalling molecules from pRBC using commercial antibodies, a 34 kDa phosphorylated molecule that possesses such ability was identified. Methods The pRBC were exposed to different culture conditions and proteins were extracted for 1D or 2D gel electrophoresis followed by Western blot. The localization of 34 kDa protein was examined by biochemical fractionation followed by Western blot. High-resolution mass spectrometric analysis of immune precipitants was used to identify this protein and real-time quantitative reverse transcriptase polymerase chain reaction was used for detecting mRNA expression level. Results The 34 kDa protein was called PfAB4 has immediate responses (dephosphorylation and rapid turnover) to host environmental stimuli such as serum depletion, osmolality change and cytokine addition. PfAB4 is expressed constitutively throughout the erythrocytic lifecycle with dominant expression in trophozoites 30 h post-infection. Tumour necrosis factor (TNF) treatment induced a transient detectable dephosphorylation of PfAB4 in the ItG strain (2 min after addition) and the level of expression and phosphorylation returned to normal within 1–2 h. PfAB4 localized dominantly in pRBC cytoplasm, with a transient shift to the nucleus under TNF stimulation as shown by biochemical fractionation. High-resolution mass spectrometric analysis of immune precipitants of AB4 antibodies revealed a 34 kDa PfAB4 component as a mixture of proliferating cellular nuclear antigen-1 (PCNA1) and exported protein-2 (EXP2), along with a small number of other inconsistently identified peptides. Different parasite strains have different PfAB4 expression levels, but no significant association between mRNA and PfAB4 levels was seen, indicating that the differences may be at the post-transcriptional, presumably phosphorylation, level. A triple serine phosphorylated PCNA1 peptide was identified from the PfAB4 high expression strain only, providing further evidence that the identity of PfAB4 is PCNA1 in P.falciparum. Conclusion A protein element in the human malaria parasite that responds to external cues, including the pro-inflammatory cytokine TNF have been discovered. Treatment results in a transient change in phosphorylation status of the response element, which also migrates from the parasite cytoplasm to the nucleus. The response element has been identified as PfPCNA1. This sensing response could be regulated by a parasite checkpoint system and be analogous to bacterial two-component signal transduction systems. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1144-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang Wu
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Laura N Cruz
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
| | - Tadge Szestak
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Gavin Laing
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Gemma R Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Celia R S Garcia
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
| | - Alister G Craig
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
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2
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Nunes MC, Goldring JPD, Doerig C, Scherf A. A novel protein kinase family in Plasmodium falciparum is differentially transcribed and secreted to various cellular compartments of the host cell. Mol Microbiol 2007; 63:391-403. [PMID: 17181785 DOI: 10.1111/j.1365-2958.2006.05521.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Processes at the surface of Plasmodium falciparum-infected erythrocytes such as antigenic variation and cytoadhesion may be modulated by active signalling between host and parasite. Potential candidates for this role include the putative kinases of the FIKK family. The novel Apicomplexa-specific FIKK gene has expanded in P. falciparum to 20 sequence-related members distributed between 11 chromosomes. Specific antibodies raised against different members indicated that most FIKK proteins locate to punctate foci in the erythrocyte cytoplasm that colocalized with Maurer's clefts proteins. One FIKK member dissociates at the trophozoite stage from the Maurer's clefts and relocates with the erythrocyte cytoskeleton. Another FIKK protein, despite having a PEXEL motif, remains located within the parasite. FIKK proteins possess the essential residues for phosphotransferase activity. We show that protein kinase activity was detected in immunoprecipitates obtained with two anti-FIKK antibodies. Quantitative PCR analysis revealed differential gene transcription of the FIKK paralogues in asexual blood stages parasites. We observed significant changes in the transcription pattern between parasites with different adhesion phenotypes. Our data suggest a role of FIKK proteins in the remodelling of the erythrocyte surface and reveal the existence of an adaptable parasite system able to sense intra- and possibly extracellular changes.
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Affiliation(s)
- Marta C Nunes
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, CNRS, 75724 Paris, France
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3
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Blisnick T, Vincensini L, Fall G, Braun-Breton C. Protein phosphatase 1, a Plasmodium falciparum essential enzyme, is exported to the host cell and implicated in the release of infectious merozoites. Cell Microbiol 2006; 8:591-601. [PMID: 16548885 DOI: 10.1111/j.1462-5822.2005.00650.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The malarial parasite Plasmodium falciparum transposes a Golgi-like compartment, referred to as Maurer's clefts, into the cytoplasm of its host cell, the erythrocyte, and delivering parasite molecules to the host cell surface. We report here a novel role of the Maurer's clefts implicating a parasite protein phosphatase 1 (PP1) and related to the phosphorylation status of P. falciparum skeleton-binding protein 1 (PfSBP1), a trans-membrane protein of the clefts interacting with the host cell membrane via its carboxy-terminal domain. Based on co-immunoprecipitation and inhibition studies, we show that the parasite PP1 type phosphatase modulates the phosphorylation status of the amino-terminal domain of PfSBP1 in the lumen of Maurer's clefts. Importantly, the addition of a PP1 inhibitor, calyculin A, to late schizonts results in the hyperphosphorylation of PfSBP1 and prevents parasite release from the host cell. We propose that the hyperphosphorylation of PfSBP1 interferes with the release of merozoites, the invasive blood stage of the parasite, by increasing the red cell membrane stability. Moreover, the parasite PP1 phosphatase is the first enzyme essential for the parasite development detected in the Maurer's clefts.
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Affiliation(s)
- Thierry Blisnick
- Unité de Biologie des Interactions Hôte-Parasite, CNRS URA 2581, France
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4
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Simões AP, Roelofsen B, Op den Kamp JA. Lipid compartmentalization in erythrocytes parasitized by Plasmodium spp. ACTA ACUST UNITED AC 2005; 8:18-21. [PMID: 15463520 DOI: 10.1016/0169-4758(92)90305-l] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although reasonably well protected from the host immune system by the erythrocyte membrane, the intraerythrocytic malaria parasite has to make that membrane compatible with its own requirements for development and multiplication. The development of Plasmodium spp brings about major changes in the lipid composition of the host cell membrane, as well as in its physical properties. The parasite itself has a lipid composition that differs from that of the host cell and an intense lipid trafficking seems to occur between intracellular parasite and host cell membrane. Here, Ana Paula Simões, Ben Roelofsen and Jos Op den Kamp discuss how, despite serious methodological limitations and the existence of some conflicting results, an overall picture of lipid compartmentalization within the parasitized erythrocyte is perceived.
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Affiliation(s)
- A P Simões
- Centre for Biomembranes and Lipid Enzymology, University of Utrecht, PO Box 80054, 3508 TB, Utrecht, The Netherlands
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5
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Abstract
Malaria is the most serious and widespread parasitic disease of humans and is arguably the commonest disease of red blood cells (RBCs). Malaria has exerted a powerful effect on human evolution and selection for resistance has led to the appearance and persistence of a number of inherited diseases. After parasite invasion, RBCs are progressively and dramatically modified. New structures appear inside the RBC and novel parasite proteins are exported to the erythrocyte cytoplasm and membrane skeleton. Radical biochemical, morphological, and rheological alterations manifest as increased membrane rigidity, reduced cell deformability, and greater adhesiveness for the vascular endothelium and other blood cells. Numerous protein-protein interactions between the malaria-parasite and the host RBC are important for many aspects of parasite biology and the pathogenesis of malaria. In addition, there are many other parasite proteins located within the infected red cell and at the membrane skeleton, for which no precise functional roles have yet been elucidated. Sequencing and annotation of the complete genome of Plasmodium falciparum, the production of proteomic and transcriptomic profiles of parasites, and the development of a transfection system for the asexual stage of the parasite are all recent achievements that should advance understanding of the molecular mechanisms that underlie the parasite-induced functional alterations in red cells.
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Affiliation(s)
- Brian M Cooke
- Department of Microbiology, Monash University, Victoria 3800, Australia
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6
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Bhattacharyya MK, Hong Z, Kongkasuriyachai D, Kumar N. Plasmodium falciparum protein phosphatase type 1 functionally complements a glc7 mutant in Saccharomyces cerevisiae. Int J Parasitol 2002; 32:739-47. [PMID: 12062492 DOI: 10.1016/s0020-7519(02)00007-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have identified a new homologue of protein phosphatase type 1 from Plasmodium falciparum, designated PfPP1, which shows 83-87% sequence identity with yeast and mammalian PP1s at the amino acid level. The PfPP1 sequence is strikingly different from all other P. falciparum Ser/Thr phosphatases cloned so far. The deduced 304 amino acid sequence revealed the signature sequence of Ser/Thr phosphatase LRGNHE, and two putative protein kinase C and five putative casein kinase II phosphorylation sites. Calyculin A, a potent inhibitor of Ser/Thr phosphatase 1 and 2A showed hyperphosphorylation of a 51kDa protein among other parasite proteins. Okadaic acid on the other hand, was without any effect suggesting that PP1 activity might predominate over PP2A activity in intra-erythrocytic P. falciparum. Complementation studies showed that PfPP1 could rescue low glycogen phenotype of Saccharomyces cerevisiae glc7 (PP1) mutant, strongly suggesting functional interaction of PfPP1 and yeast proteins involved in glycogen metabolism.
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Affiliation(s)
- Mrinal K Bhattacharyya
- Johns Hopkins Malaria Research Institute, The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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7
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Cooke BM, Mohandas N, Coppel RL. The malaria-infected red blood cell: structural and functional changes. ADVANCES IN PARASITOLOGY 2001; 50:1-86. [PMID: 11757330 PMCID: PMC7130133 DOI: 10.1016/s0065-308x(01)50029-9] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The asexual stage of malaria parasites of the genus Plasmodium invade red blood cells of various species including humans. After parasite invasion, red blood cells progressively acquire a new set of properties and are converted into more typical, although still simpler, eukaryotic cells by the appearance of new structures in the red blood cell cytoplasm, and new proteins at the red blood cell membrane skeleton. The red blood cell undergoes striking morphological alterations and its rheological properties are considerably altered, manifesting as red blood cells with increased membrane rigidity, reduced deformability and increased adhesiveness for a number of other cells including the vascular endothelium. Elucidation of the structural changes in the red blood cell induced by parasite invasion and maturation and an understanding of the accompanying functional alterations have the ability to considerably extend our knowledge of structure-function relationships in the normal red blood cell. Furthermore, interference with these interactions may lead to previously unsuspected means of reducing parasite virulence and may lead to the development of novel antimalarial therapeutics.
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Affiliation(s)
- B M Cooke
- Department of Microbiology, P.O. Box 53, Monash University, Victoria 3800, Australia
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8
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Li J, Cox LS. Isolation and characterisation of a cAMP-dependent protein kinase catalytic subunit gene from Plasmodium falciparum. Mol Biochem Parasitol 2000; 109:157-63. [PMID: 10960174 DOI: 10.1016/s0166-6851(00)00242-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- J Li
- Department of Biochemistry, University of Oxford, UK.
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9
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Li JL, Baker DA. Protein phosphatase beta, a putative type-2A protein phosphatase from the human malaria parasite Plasmodium falciparum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 249:98-106. [PMID: 9363759 DOI: 10.1111/j.1432-1033.1997.t01-2-00098.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Protein phosphatases play a critical role in the regulation of the eukaryotic cell cycle and signal transduction. A putative protein serine/threonine phosphatase gene has been isolated from the human malaria parasite Plasmodium falciparum. The gene has an unusual intron that contains four repeats of 32 nucleotides and displays a high degree of size polymorphism among different strains of P. falciparum. The open reading frame reconstituted by removal of the intron encodes a protein of 466 amino acids with a predicted molecular mass of approximately 53.7 kDa. The encoded protein, termed protein phosphatase beta (PP-beta), is composed of two distinct domains. The C-terminal domain comprises 315 amino acids and exhibits a striking similarity to the catalytic subunits of the type-2A protein phosphatases. Database searches revealed that the catalytic domain has the highest similarity to Schizosaccharomyces pombe Ppa1 (58% identity and 73% similarity). However, it contains a hydrophilic insert consisting of five amino acids. The N-terminal domain comprises 151 amino acid residues and exhibits several striking features, including high levels of charged amino acids and asparagine, and multiple consensus phosphorylation sites for a number of protein kinases. An overall structural comparison of PP-beta with other members of the protein phosphatase 2A group revealed that PP-beta is more closely related to Saccharomyces cerevisiae PPH22. Southern blots of genomic DNA digests and chromosomal separations showed that PP-beta is a single-copy gene and is located on chromosome 9. A 2800-nucleotide transcript of this gene is expressed specifically in the sexual erythrocytic stage (gametocytes). The results indicate that PP-beta may be involved in sexual stage development.
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Affiliation(s)
- J L Li
- Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK
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10
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Lin DT, Goldman ND, Syin C. Stage-specific expression of a Plasmodium falciparum protein related to the eukaryotic mitogen-activated protein kinases. Mol Biochem Parasitol 1996; 78:67-77. [PMID: 8813678 DOI: 10.1016/s0166-6851(96)02608-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have identified a putative protein kinase gene from both Plasmodium falciparum cDNA and genomic DNA libraries. The nucleotide sequence contains an open-reading frame of 2646 bp, which codes for a predicted protein of 882 amino acid residues. Comparison of the predicted amino acid sequence with those in GenBank suggests that this gene codes for a protein similar to the mitogen-activated protein (MAP) kinase of other organisms. This MAP kinase-related protein, named PfMRP, contains the TDY dual phosphorylation site upstream of the highly conserved VATRWYRAPE sequence in subdomain VIII. PfMRP contains an unusually large and highly charged domain within its carboxyl-terminal segment, which includes two repetitive sequences of either a tetrapeptide or octapeptide motif. PfMRP gene is located on chromosome 14. Northern blot analysis of total RNA reveals the presence of a single mRNA transcript approximately 4.2 kb in length, which is predominantly expressed in gametocytes and gametes/zygotes.
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Affiliation(s)
- D T Lin
- Laboratory of Parasitic Biology and Biochemistry, Food and Drug Administration, Rockville, MD 20852-1448, USA
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11
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Shimizu T, Takakuwa Y, Koizumi H, Ishibashi T, Ohkawara A. Localization of immuno-analogues of erythrocyte protein 4.1 and spectrin in epidermis of psoriasis vulgaris. Histochem Cell Biol 1995; 103:363-8. [PMID: 7641068 DOI: 10.1007/bf01457811] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The presence and localization of immuno-analogues of human erythrocyte protein 4.1 and spectrin were examined in the epidermis of psoriasis vulgaris. Immunoblot analysis with antibodies against human erythrocyte protein 4.1 revealed that psoriatic epidermis contains a 4.1-like protein of 80 kDa, and also minor immunoreactive polypeptides, including a 45-kDa polypeptide. The 45-kDa band was not detected in non-lesional epidermis. Lesional epidermis of psoriasis contains spectrin-like proteins of 240 kDa. Analysis with immunofluorescence microscopy revealed that 4.1-like proteins were detected mainly in the cytoplasm of the suprabasal cells in lesional epidermis and in the peripheral cytoplasm of the basal cells in non-lesional epidermis. On the other hand, spectrin-like proteins were localized to the peripheral cytoplasm of basal keratinocytes in both lesional and non-lesional psoriatic epidermis. The present results indicate that proteins related to protein 4.1 and spectrin are consistently detected within epidermal cells of psoriasis, a chronic skin disease characterized by epidermal hyperplasia; the expression and distribution of protein 4.1 in lesional epidermis of psoriasis differs from that in non-lesional epidermis. These membrane skeletal proteins may be of significance in the hyperproliferative epidermis of psoriasis.
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Affiliation(s)
- T Shimizu
- Department of Dermatology, Hokkaido University School of Medicine, Sapporo, Japan
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12
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Kappes B, Suetterlin BW, Hofer-Warbinek R, Humar R, Franklin RM. Two major phosphoproteins of Plasmodium falciparum are heat shock proteins. Mol Biochem Parasitol 1993; 59:83-94. [PMID: 8515785 DOI: 10.1016/0166-6851(93)90009-m] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Two major phosphoproteins of Plasmodium falciparum could be identified by partial amino acid sequencing as the plasmodial members of the hsp 70 heat shock protein family, Pfhsp and Pfgrp. According to phosphoamino acid analyses of Pfhsp and Pfgrp isolated from [32P]orthophosphate-labeled malarial cultures, both proteins were phosphorylated in Ser and Thr. While Pfhsp contains higher amounts of labeled phosphoserine, Pfgrp contains higher amounts of phosphothreonine. Phosphorylation of both proteins increased throughout the entire erythrocytic growth cycle. At the trophozoite and schizont stages Pfhsp and Pfgrp are the most prominent phosphoproteins of Plasmodium falciparum. Using multiply redundant oligonucleotides directed against the N-terminus of Pfgrp we cloned and sequenced the entire Pfgrp gene. The gene encodes a product with a predicted length of 652 amino acids. The deduced amino acid sequence has identities of 65.5% and 65.0% to the human and rat grp78 proteins, respectively. Pfgrp possesses a classical N-terminal leader sequence. The published grp78 related gene sequences of Plasmodium falciparum are all fragments of the same plasmodial gene.
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Affiliation(s)
- B Kappes
- Department of Structural Biology, University of Basel, Switzerland
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13
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Gene structure and expression of an unusual protein kinase from Plasmodium falciparum homologous at its carboxyl terminus with the EF hand calcium-binding proteins. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53616-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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14
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Suetterlin BW, Kappes B, Jenoe P, Franklin RM. An 88-kDa protein of Plasmodium falciparum is related to the band-3-binding domain of human erythrocyte ankyrin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:455-61. [PMID: 1386021 DOI: 10.1111/j.1432-1033.1992.tb17071.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Three tryptic-peptide sequences of an 88-kDa pair of phosphoproteins of the malaria parasite Plasmodium falciparum were determined. They exhibit a striking similarity to corresponding sequences of the 89-kDa domain of human erythrocyte ankyrin. [35S]Methionine labeling of the two proteins demonstrated their parasitic origin. Using an appropriate oligonucleotide probe, Southern-blot analysis of genomic malaria DNA and Northern-blot analysis of malaria RNA suggest the existence of ankyrin-related sequences in the parasite genome and the presence of an ankyrin-related transcript of about 3.2 kb. Our studies provide further evidence of malaria-specific analogues of host-cell proteins, implying an unusual kind of parasite/host interaction.
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15
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Zhao Y, Kappes B, Yang J, Franklin RM. Molecular cloning, stage-specific expression and cellular distribution of a putative protein kinase from Plasmodium falciparum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:305-13. [PMID: 1378403 DOI: 10.1111/j.1432-1033.1992.tb17051.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A putative protein kinase gene (PfPK2) has been isolated from the human parasite Plasmodium falciparum by using a mixed oligonucleotide pool which corresponds to a highly conserved region of serine/threonine protein kinases. The complete nucleotide sequence of 5 kb suggests the existence of a second transcriptional unit besides that of the PfPK2 gene, separated by a highly (A+T)-rich region and transcribed in a different orientation. No intron sequence exists in PfPK2. The predicted amino acid sequence of PfPK2 contains features characteristic of eukaryotic serine/threonine protein kinases. Within its putative catalytic domain it shares 33%, 30%, and 28% amino acid identities with rat calcium-calmodulin-dependent protein kinase, human protein kinase C, and bovine cAMP-dependent protein kinase, respectively. Outside the catalytic domain, however, PfPK2 has no homology with regulatory domains of other protein kinases, indicating PfPK2 might be modulated by signals different from those of higher eukaryotes or might be associated with other regulatory subunits. Using a specific antiserum raised in rabbits against a recombinant fragment of the protein expressed in Escherichia coli, PfPK2 was found to be expressed in a stage-specific fashion and mainly localized in the parasitic membrane.
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Affiliation(s)
- Y Zhao
- Department of Structural Biology, Biocenter of the University of Basel, Switzerland
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16
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Abstract
Several distinct classes of Plasmodium proteins have been proposed to interact with the submembrane skeleton of the erythrocyte based upon differential solubility and subcellular localization studies. That the parasite affects the erythrocyte membrane by interacting with the submembrane skeleton is an attractive hypothesis since the membrane skeleton likely regulates many aspects of membrane topography and function. The precise interactions between host and parasite proteins at the molecular level and how the parasite proteins are transported to the erythrocyte membrane are not completely understood. Experiments addressing these questions are under way, and such studies will provide valuable information about the host-parasite interface. In addition, the characterization of the interaction of Plasmodium proteins with the host erythrocyte membrane may also provide new insight into the structure and function of the erythrocyte membrane or membranes in general.
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Affiliation(s)
- M F Wiser
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Medical Center, New Orleans, Louisiana 70112
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17
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Chao TS, Tao M. Modulation of protein 4.1 binding to inside-out membrane vesicles by phosphorylation. Biochemistry 1991; 30:10529-35. [PMID: 1931975 DOI: 10.1021/bi00107a023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effect of phosphorylation on the binding of protein 4.1 to erythrocyte inside-out vesicles was investigated. Protein 4.1 was phosphorylated with casein kinase A, protein kinase C, and cAMP-dependent protein kinase. An analysis of the phosphopeptides generated by alpha-chymotryptic and tryptic digestion indicates these kinases phosphorylate similar as well as distinct domains within protein 4.1. All three enzymes catalyze the phosphorylation to varying degrees of the 46-, 16-, and 8-10-kDa fragments derived from limited chymotryptic cleavage. In addition, casein kinase A phosphorylates a 24-kDa domain, whereas protein kinase C phosphorylates a 30-kDa domain. Protein 4.1 phosphorylated by casein kinase A and protein kinase C, but not cAMP-dependent protein kinase, exhibits a reduced binding to KI-extracted inside-out vesicles. On the other hand, phosphorylation of inside-out vesicles by casein kinase A does not affect their ability to bind protein 4.1. The inside-out vesicles, however, inhibit the phosphorylation of protein 4.1 by casein kinase A and protein kinase C, but not by cAMP-dependent protein kinase. These results suggest that casein kinase A and protein kinase C may modulate the binding of protein 4.1 to the membrane by phosphorylation of specific domains of the cytoskeletal protein. Since the 30-kDa domain has been suggested as a membrane-binding site, that phosphorylation by protein kinase C reduces the binding of protein 4.1 to inside-out vesicles is perhaps not surprising. On the other hand, the role of the casein kinase A substrate 24-kDa domain in membrane binding has not been established and needs to be examined.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T S Chao
- Department of Biochemistry, College of Medicine, University of Illinois, Chicago 60612
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18
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Suetterlin BW, Kappes B, Franklin RM. Localization and stage specific phosphorylation of Plasmodium falciparum phosphoproteins during the intraerythrocytic cycle. Mol Biochem Parasitol 1991; 46:113-22. [PMID: 1852167 DOI: 10.1016/0166-6851(91)90205-k] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fifty-nine Plasmodium falciparum specific phosphoproteins with molecular weights between 15,000 and 192,000 were analyzed by SDS-PAGE and two-dimensional gel electrophoresis. 40 phosphoproteins were identified by [gamma-32P]ATP labeling of cell lysates, 19 by [32P]orthophosphate labeling of parasitic cultures in vivo. Changes in the phosphorylation pattern during the infectious erythrocytic cycle were determined for all proteins. In parallel, cell fractionation studies were done to follow up possible changes in the cellular distribution of these proteins. Several phosphoproteins are associated with the membrane fraction of infected erythrocytes. One pair of proteins of approx. 88 kDa and a pI of about 5.0 was further characterized. Both proteins are located in the parasitic fractions as well as in the membrane of infected erythrocytes during the entire cycle. Phosphorylation of these proteins, however, is restricted to the trophozoite and schizont stages. Peptide mapping studies demonstrated that both proteins are identical with the exception of minor modifications which are probably not the result of differences in phosphorylation.
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Affiliation(s)
- B W Suetterlin
- Biocenter, Department of Structural Biology, Basel, Switzerland
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19
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Jones GL, Edmundson HM. Protein phosphorylation during the asexual life cycle of the human malarial parasite Plasmodium falciparum. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1053:118-24. [PMID: 2200523 DOI: 10.1016/0167-4889(90)90002-u] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent evidence has suggested that extensive changes in the phosphorylation profile of red cell membrane proteins are associated with the invasion and development of the malarial parasite. In order to further define the role of parasite protein phosphorylation in these events we have looked at this phosphorylation using: (1) continuous metabolic labelling with [32P]orthophosphate, (2) pulse-labelling with [32P]orthophosphate and [35S]methionine, (3) autophosphorylation of infected cells using [gamma-32P]ATP, (4) invasion of prelabelled red cells. Many parasite proteins were labelled, some differentially according to the phosphorylation protocol employed, and we were able to partially characterise several of the major parasite phosphoproteins in terms of their association with host cell membrane and the stage specificity of phosphorylation.
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Affiliation(s)
- G L Jones
- Queensland Institute of Medical Research, Herston, Australia
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Danilov YN, Fennell R, Ling E, Cohen CM. Selective modulation of band 4.1 binding to erythrocyte membranes by protein kinase C. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39837-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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