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Shekhar S, Verma S, Gupta MK, Roy SS, Kaur I, Krishnamachari A, Dhar SK. Genome-wide binding sites of Plasmodium falciparum mini chromosome maintenance protein MCM6 show new insights into parasite DNA replication. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119546. [PMID: 37482133 DOI: 10.1016/j.bbamcr.2023.119546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 07/08/2023] [Accepted: 07/16/2023] [Indexed: 07/25/2023]
Abstract
Multiple rounds of DNA replication take place in various stages of the life cycle in the human malaria parasite Plasmodium falciparum. Previous bioinformatics analysis has shown the presence of putative Autonomously Replicating Sequence (ARS) like sequences in the Plasmodium genome. However, the actual sites and frequency of replication origins in the P. falciparum genome based on experimental data still remain elusive. Minichromosome maintenance (MCM) proteins are recruited by the Origin recognition complex (ORC) to the origins of replication in eukaryotes including P. falciparum. We used PfMCM6 for chromatin immunoprecipitation followed by sequencing (ChIP-seq) in the quest for identification of putative replication origins in the parasite. PfMCM6 DNA binding sites annotation revealed high enrichment at exon regions. This is contrary to higher eukaryotes that show an inclination of origin sites towards transcriptional start sites. ChIP-seq results were further validated by ChIP-qPCR results as well as nascent strand abundance assay at the selected PfMCM6 enriched sites that also showed preferential binding of PfORC1 suggesting potential of these sites as origin sites. Further, PfMCM6 ChIP-seq data showed a positive correlation with previously published histone H4K8Ac genome-wide binding sites but not with H3K9Ac sites suggesting epigenetic control of replication initiation sites in the parasites. Overall, our data show the genome-wide distribution of PfMCM6 binding sites with their potential as replication origins in this deadly human pathogen that not only broadens our knowledge of parasite DNA replication and its unique biology, it may help to find new avenues for intervention processes.
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Affiliation(s)
- Shashank Shekhar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Sunita Verma
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Mohit Kumar Gupta
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Sourav Singha Roy
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Inderjeet Kaur
- Department of Biotechnology, Central University of Haryana, Mahendergargh, India
| | | | - Suman Kumar Dhar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
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Johnson N, Philip N. Beyond phosphorylation: Putative roles of post-translational modifications in Plasmodium sexual stages. Mol Biochem Parasitol 2021; 245:111406. [PMID: 34324911 PMCID: PMC8505795 DOI: 10.1016/j.molbiopara.2021.111406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 07/07/2021] [Accepted: 07/22/2021] [Indexed: 11/26/2022]
Abstract
Post-translational modifications (PTMs) allow proteins to regulate their structure, localisation and function in response to cell intrinsic and environmental signals. The diversity and number of modifications on proteins increase the complexity of cellular proteomes by orders of magnitude. Several proteomic and molecular studies have revealed an abundance of PTMs in malaria parasite proteome, where mediators of PTMs play crucial roles in parasite pathogenesis and transmission. In this article, we discuss recent findings in asexual stages of ten diverse PTMs and investigate whether these proteins are expressed in sexual stages. We discovered 25-50 % of proteins exhibiting post-translational modifications in asexual stages are also expressed in sexual stage gametocytes. Moreover we analyse the function of the modified proteins shared with the gametocyte proteome and try to encourage the scientific community to investigate the roles of diverse PTMs beyond phosphorylation in sexual stages which could not only reveal unique aspects of parasite biology, but also uncover new avenues for transmission blocking.
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Affiliation(s)
- Nila Johnson
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Nisha Philip
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK.
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Structural insights into histone chaperone Asf1 and its characterization from Plasmodium falciparum. Biochem J 2021; 478:1117-1136. [PMID: 33501928 DOI: 10.1042/bcj20200891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 02/06/2023]
Abstract
Asf1 is a highly conserved histone chaperone that regulates tightly coupled nucleosome assembly/disassembly process. We observed that Plasmodium falciparum Asf1 (PfAsf1) is ubiquitously expressed in different stages of the life cycle of the parasite. To gain further insight into its biological activity, we solved the structure of N-terminal histone chaperone domain of PfAsf1 (1-159 amino acids) by X-ray crystallography to a resolution of 2.4 Å. The structure is composed of two beta-sheet to form a beta-sandwich, which resembles an immunoglobulin-like fold. The surface-charge distribution of PfAsf1 is distinct from yAsf1 and hAsf1 although the core-structure shows significant similarity. The crystal-structure indicated that PfAsf1 may exist in a dimeric-state which was further confirmed by solution cross-linking experiment. PfAsf1 was found to specifically interact with Plasmodium histone H3 and H4 and was able to deposit H3/H4 dimer onto DNA-template to form disomes, showing its characteristic histone chaperone activity. We mapped the critical residues of PfAsf1 involved in histone H3/H4 interaction and confirmed by site-directed mutagenesis. Further analysis indicates that histone interacting surface of Asf1 is highly conserved while the dimerization interface is variable. Our results identify the role of PfAsf1 as a mediator of chromatin assembly in Plasmodium falciparum, which is the causative agent of malignant malaria in humans.
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Kaushik M, Nehra A, Gakhar SK, Gill SS, Gill R. The multifaceted histone chaperone RbAp46/48 in Plasmodium falciparum: structural insights, production, and characterization. Parasitol Res 2020; 119:1753-1765. [PMID: 32363442 DOI: 10.1007/s00436-020-06669-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 03/15/2020] [Indexed: 12/31/2022]
Abstract
RbAp46/RBBP7 and RbAp48/RBBP4 are WD40-repeat histone chaperones and chromatin adaptors that reside in multiple complexes involved in maintenance of chromatin structure. RbAp48 is the essential subunit of the chromatin assembly factor-1 (CAF-1) complex, therefore also named as CAF-1C. A detailed in silico sequence and structure analysis of homologs of RbAp46/48 in Plasmodium falciparum (PF3D7_0110700 and PF3D7_1433300) exhibited conservation of characteristic features in both the protein-seven-bladed WD40 β-propeller conformation and different binding interfaces. A comparative structural analysis highlighted species-specific features of the parasite, yeast, drosophila, and human RbAp46/48. In the present study, we report cloning, expression, and characterization of P. falciparum PF3D7_0110700, a putative RbAp46/48 (PfRbAp46/48). PfRbAp46/48 was cloned into pTEM11 vector in fusion with 6xHistidine tag and over-expressed in Escherichia coli B834 cells. The protein was purified by Ni-NTA followed by gel permeation chromatography. The protein expressed in all the three asexual blood stages and exhibited nuclear localization. We showed direct interaction of the purified rPfRbAp46/48 with the histone H4. These findings further our understanding of RbAp46/48 proteins and role of these proteins in the parasite biology.
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Affiliation(s)
- Manjeri Kaushik
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Ashima Nehra
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Surendra Kumar Gakhar
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Sarvajeet Singh Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Ritu Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India.
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Kaushik M, Nehra A, Gill SS, Gill R. Unraveling CAF-1 family in Plasmodium falciparum: comparative genome-wide identification and phylogenetic analysis among eukaryotes, expression profiling and protein-protein interaction studies. 3 Biotech 2020; 10:143. [PMID: 32206492 DOI: 10.1007/s13205-020-2096-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 01/24/2020] [Indexed: 11/29/2022] Open
Abstract
The present research reports a detailed in silico analysis of chromatin assembly factor-1 (CAF-1) family in human malaria parasite Plasmodium falciparum. Our analysis revealed five chromatin assembly factor-1 genes in P. falciparum (PfCAF-1) and the PfCAF-1 family was divided into two classes where, Class A belongs to the CAF-1 complex and others are kept in Class B. For comparative studies, orthologs of PfCAF-1 family were identified across 53 eukaryotic species and evolutionary relationships were drawn for different CAF-1 subfamilies. The phylogenetic analysis revealed grouping of evolutionary-related species together, although, divergence was observed in branching pattern. A detailed analysis of domain composition highlighted species-specific features viz. species-specific KDDS repeats of 84 amino acids were identified in PfCAF-1A whereas, members of CAF-1C/RbAp48 and RbAp46 subfamily exhibited least variation in size and domain composition. The qRT-PCR analysis revealed upregulation of PfCAF-1 members in trophozoite or schizont stage. Furthermore, a comparative expression analysis of the available transcriptome and proteome data along with qRT-PCR analysis revealed mixed expression patterns (coordination as well as non-coordination between different studies). Protein-protein interaction network analyses of PfCAF-1 family were carried out highlighting important complexes based on interologs. The PfRbAp48 was found to be highly connected with a total of 108 PPIs followed by PfRbAp46. The results unravel insights into the PfCAF-1 family and identify unique features, thus opening new perspectives for further targeted developments to understand and combat malaria menace.
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Affiliation(s)
- Manjeri Kaushik
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana 124 001 India
| | - Ashima Nehra
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana 124 001 India
| | - Sarvajeet Singh Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana 124 001 India
| | - Ritu Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana 124 001 India
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Bhowmick K, Tehlan A, Sunita, Sudhakar R, Kaur I, Sijwali PS, Krishnamachari A, Dhar SK. Plasmodium falciparum GCN5 acetyltransferase follows a novel proteolytic processing pathway that is essential for its function. J Cell Sci 2020; 133:jcs.236489. [PMID: 31862795 DOI: 10.1242/jcs.236489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 11/29/2019] [Indexed: 12/18/2022] Open
Abstract
The pathogenesis of human malarial parasite Plasmodium falciparum is interlinked with its timely control of gene expression during its complex life cycle. In this organism, gene expression is partially controlled through epigenetic mechanisms, the regulation of which is, hence, of paramount importance to the parasite. The P. falciparum (Pf)-GCN5 histone acetyltransferase (HAT), an essential enzyme, acetylates histone 3 and regulates global gene expression in the parasite. Here, we show the existence of a novel proteolytic processing for PfGCN5 that is crucial for its activity in vivo We find that a cysteine protease-like enzyme is required for the processing of PfGCN5 protein. Immunofluorescence and immuno-electron microscopy analysis suggest that the processing event occurs in the vicinity of the digestive vacuole of the parasite following its trafficking through the classical ER-Golgi secretory pathway, before it subsequently reaches the nucleus. Furthermore, blocking of PfGCN5 processing leads to the concomitant reduction of its occupancy at the gene promoters and a reduced H3K9 acetylation level at these promoters, highlighting the important correlation between the processing event and PfGCN5 activity. Altogether, our study reveals a unique processing event for a nuclear protein PfGCN5 with unforeseen role of a food vacuolar cysteine protease. This leads to a possibility of the development of new antimalarials against these targets.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Krishanu Bhowmick
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ankita Tehlan
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sunita
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Renu Sudhakar
- Centre for Cellular and Molecular Biology, Hyderabad, Telengana 500007, India
| | - Inderjeet Kaur
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Puran Singh Sijwali
- Centre for Cellular and Molecular Biology, Hyderabad, Telengana 500007, India
| | | | - Suman Kumar Dhar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
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Anas M, Kumari V, Gupta N, Dube A, Kumar N. Protein quality control machinery in intracellular protozoan parasites: hopes and challenges for therapeutic targeting. Cell Stress Chaperones 2019; 24:891-904. [PMID: 31228085 PMCID: PMC6717229 DOI: 10.1007/s12192-019-01016-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/28/2023] Open
Abstract
Intracellular protozoan parasites have evolved an efficient protein quality control (PQC) network comprising protein folding and degradation machineries that protect the parasite's proteome from environmental perturbations and threats posed by host immune surveillance. Interestingly, the components of PQC machinery in parasites have acquired sequence insertions which may provide additional interaction interfaces and diversify the repertoire of their biological roles. However, the auxiliary functions of PQC machinery remain poorly explored in parasite. A comprehensive understanding of this critical machinery may help to identify robust biological targets for new drugs against acute or latent and drug-resistant infections. Here, we review the dynamic roles of PQC machinery in creating a safe haven for parasite survival in hostile environments, serving as a metabolic sensor to trigger transformation into phenotypically distinct stages, acting as a lynchpin for trafficking of parasite cargo across host membrane for immune evasion and serving as an evolutionary capacitor to buffer mutations and drug-induced proteotoxicity. Versatile roles of PQC machinery open avenues for exploration of new drug targets for anti-parasitic intervention and design of strategies for identification of potential biomarkers for point-of-care diagnosis.
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Affiliation(s)
- Mohammad Anas
- Department of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Varsha Kumari
- Department of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Niharika Gupta
- Department of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Anuradha Dube
- Department of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Niti Kumar
- Academy of Scientific and Innovative Research (AcSIR), Delhi, India.
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