Biochemical characterization of the two nucleosome assembly proteins from Plasmodium falciparum

Chandra, Beeram Ravi; Olivieri, Anna; Silvestrini, Francesco; Alano, Pietro; Sharma, Amit

doi:10.1016/j.molbiopara.2005.04.006

Cited by 42 publications

(69 citation statements)

References 26 publications

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“…Plasmid supercoiling assays suggest that PfNapS is able to deposit histones onto DNA, whereas PfNapL is not. This is in agreement with the nuclear localization of PfNapS and the predominantly cytoplasmic positioning of PfNapL (1). Histone deposition by PfNapS requires divalent cations, and the process is ATP-independent.…”

supporting

confidence: 87%

“…Both of these proteins form complexes with histone tetramer [(H3-H4) 2 ] as well as histone octamer (formed by two heterodimers of H2A-H2B and a tetramer of histone H3-histone H4) (1). Here, we show that PfNapS and PfNapL, apart from interacting with core histones, also interact with the linker histone H1.…”

mentioning

confidence: 68%

“…We have recently described two nucleosome assembly proteins from P. falciparum, PfNapS and PfNapL (1). Both of these proteins form complexes with histone tetramer [(H3-H4) 2 ] as well as histone octamer (formed by two heterodimers of H2A-H2B and a tetramer of histone H3-histone H4) (1).…”

mentioning

confidence: 99%

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The Two Plasmodium falciparum Nucleosome Assembly Proteins Play Distinct Roles in Histone Transport and Chromatin Assembly

Navadgi

Chandra

Mishra

et al. 2006

Journal of Biological Chemistry

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The malarial parasite Plasmodium falciparum has two nucleosome assembly proteins, PfNapS and PfNapL (Chandra, B. R., Olivieri, A., Silvestrini, F., Alano, P., and Sharma, A. (2005) Mol. Biochem. Parasitol. 142, 237-247). We show that both PfNapS and PfNapL interact with histone oligomers but only PfNapS is able to deposit histones onto DNA. This property of PfNapS is divalent cation-dependent and ATP-independent. Deletion of the terminal subdomains of PfNapS abolishes its nucleosome assembly capabilities, but the truncated protein retains its ability to bind histones. Both PfNapS and PfNapL show binding to the linker histone H1 suggesting their probable role in extraction of H1 from chromatin fibers. Our data suggests distinct sites of interaction for H1 versus H3/H4 on PfNapS. We show that PfNapS and PfNapL are phosphorylated both in vivo and in vitro by casein kinase-II, and this modification is specifically inhibited by heparin. Circular dichroism, fluorescence spectroscopy, and chymotrypsin fingerprinting data together suggest that PfNapL may undergo very small and subtle structural changes upon phosphorylation. Specifically, phosphorylation of PfNapL increases its affinity 3-fold for core histones H3, H4, and for the linker histone H1. Finally, we demonstrate that PfNapS is able to extract histones from both phosphorylated and unphosphorylated PfNapL, potentially for histone deposition onto DNA. Based on these results, we suggest that the P. falciparum NapL is involved in the nucleocytoplasmic relay of histones, whereas PfNapS is likely to be an integral part of the chromatin assembly motors in the parasite nucleus.

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supporting

confidence: 87%

mentioning

confidence: 68%

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The Two Plasmodium falciparum Nucleosome Assembly Proteins Play Distinct Roles in Histone Transport and Chromatin Assembly

Navadgi

Chandra

Mishra

et al. 2006

Journal of Biological Chemistry

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“…A further purification step of gel permeation chromatography and ion-exchange chromatography was carried out to purify target proteins. Antibodies against PfMRSs were generated in rabbits, and previously characterized antibodies against parasite proteins were used as controls where appropriate (28,29).…”

Section: Methodsmentioning

confidence: 99%

“…Several critical malaria parasite processes, including nucleosome assembly and lipid import in the malaria parasites, have been studied using structure-function techniques (29,(48)(49)(50)(51). However, in these and similar cases, a lack of experimentally verified inhibitors has hampered drug development to date.…”

Section: Pfmrsmentioning

confidence: 99%

Inhibition of Protein Synthesis and Malaria Parasite Development by Drug Targeting of Methionyl-tRNA Synthetases

Hussain

Yogavel

Sharma

2015

Antimicrob Agents Chemother

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Aminoacyl-tRNA synthetases (aaRSs) are housekeeping enzymes that couple cognate tRNAs with amino acids to transmit genomic information for protein translation. The Plasmodium falciparum nuclear genome encodes two P. falciparum methionyl-tRNA synthetases (PfMRS), termed PfMRS cyt and PfMRS api . Phylogenetic analyses revealed that the two proteins are of primitive origin and are related to heterokonts (PfMRS cyt ) or proteobacteria/primitive bacteria (PfMRS api ). We show that PfMRS cyt localizes in parasite cytoplasm, while PfMRS api localizes to apicoplasts in asexual stages of malaria parasites. Two known bacterial MRS inhibitors, REP3123 and REP8839, hampered Plasmodium growth very effectively in the early and late stages of parasite development. Small-molecule drug-like libraries were screened against modeled PfMRS structures, and several "hit" compounds showed significant effects on parasite growth. We then tested the effects of the hit compounds on protein translation by labeling nascent proteins with 35 S-labeled cysteine and methionine. Three of the tested compounds reduced protein synthesis and also blocked parasite growth progression from the ring stage to the trophozoite stage. Drug docking studies suggested distinct modes of binding for the three compounds, compared with the enzyme product methionyl adenylate. Therefore, this study provides new targets (PfMRSs) and hit compounds that can be explored for development as antimalarial drugs. P lasmodium falciparum is the most virulent form of Plasmodium and a causative agent of malaria. The World Health Organization (WHO) estimates that there are ϳ0.62 million deaths due to malaria per year (1). The P. falciparum genome is AT-rich (81%) and codes for ϳ5,300 proteins, with unusual distributions of several residues (2). Almost 60% of encoded proteins appear to be unique to the parasite, reflecting great evolutionary distance between the parasite and the genomes of known eukaryotes (3). The malaria parasite (and the related apicomplexan Toxoplasma gondii) has three translationally active compartments, i.e., cytoplasm, apicoplasts, and mitochondria (4-8). All malaria parasite proteins involved in the protein synthesis machinery are encoded by the nuclear genome. Either these proteins are transported to target organelles or their modified/activated substrates are transported across the organelles to perform required functions (4-9). The primary enzymes responsible for translating genetic code into polypeptide chains are aminoacyl-tRNA synthetases (aaRSs). The canonical function of aaRSs is to ligate a specific amino acid to its cognate tRNA, which is then employed in protein synthesis. The aaRSs are an ancient class of essential enzymes, and their catalytic domains are conserved in all kingdoms (bacteria, archaebacteria, and eukaryotes). On the basis of catalytic domain architecture, aaRSs are classified into two categories, with each class containing ϳ10 aaRSs (10). Although aaRSs perform the basic function of charging tRNA molecules for protein synthesis, a...

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Plasmodium falciparum HSP40 protein eCiJp traffics to the erythrocyte cytoskeleton and interacts with the human HSP70 chaperone HSPA1

et al. 2021

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Renovation of host erythrocytes is vital for pathogenesis by Plasmodium falciparum. These changes are mediated by parasite proteins that translocate beyond the parasitophorous vacuolar membrane in an unfolded state, suggesting protein folding by chaperones is imperative for the functionality of exported proteins. We report a type IV P. falciparum heat-shock protein 40, PF11_0034, that localizes to the cytoplasmic side of J-dots and interacts with the erythrocyte cytoskeleton, and therefore named eCiJp (erythrocyte cytoskeleton-interacting J protein). Recombinant eCiJp binds to the human heat-shock protein 70 HsHSPA1 and promotes its ATPase activity. In addition, eCiJp could suppress protein aggregation. Our data suggest that eCiJp recruits HsHSPA1 to the host erythrocyte cytoskeleton, where it may become involved in remodeling of the erythrocyte cytoskeleton and/or folding of exported parasite proteins.

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Biochemical characterization of the two nucleosome assembly proteins from Plasmodium falciparum

Cited by 42 publications

References 26 publications

The Two Plasmodium falciparum Nucleosome Assembly Proteins Play Distinct Roles in Histone Transport and Chromatin Assembly

The Two Plasmodium falciparum Nucleosome Assembly Proteins Play Distinct Roles in Histone Transport and Chromatin Assembly

Inhibition of Protein Synthesis and Malaria Parasite Development by Drug Targeting of Methionyl-tRNA Synthetases

Plasmodium falciparum HSP40 protein eCiJp traffics to the erythrocyte cytoskeleton and interacts with the human HSP70 chaperone HSPA1

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