1
|
Liu C, Tang J, Liang K, Liu P, Li Z. Ready for renascence in mosquito: The regulation of gene expression in Plasmodium sexual development. Acta Trop 2024; 254:107191. [PMID: 38554994 DOI: 10.1016/j.actatropica.2024.107191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/21/2024] [Accepted: 03/18/2024] [Indexed: 04/02/2024]
Abstract
Malaria remains one of the most perilous vector-borne infectious diseases for humans globally. Sexual gametocyte represents the exclusive stage at which malaria parasites are transmitted from the vertebrate to the Anopheles host. The feasible and effective approach to prevent malaria transmission is by addressing the sexual developmental processes, that is, gametocytogenesis and gametogenesis. Thus, this review will comprehensively cover advances in the regulation of gene expression surrounding the transmissible stages, including epigenetic, transcriptional, and post-transcriptional control.
Collapse
Affiliation(s)
- Cong Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China; School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Jingjing Tang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Kejia Liang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Peng Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Zhenkui Li
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| |
Collapse
|
2
|
Kalamuddin M, Shakri AR, Wang C, Min H, Li X, Cui L, Miao J. MYST regulates DNA repair and forms a NuA4-like complex in the malaria parasite Plasmodium falciparum. mSphere 2024; 9:e0014024. [PMID: 38564734 PMCID: PMC11036802 DOI: 10.1128/msphere.00140-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
Histone lysine acetyltransferase MYST-associated NuA4 complex is conserved from yeast to humans and plays key roles in cell cycle regulation, gene transcription, and DNA replication/repair. Here, we identified a Plasmodium falciparum MYST-associated complex, PfNuA4, which contains 11 of the 13 conserved NuA4 subunits. Reciprocal pulldowns using PfEAF2, a shared component between the NuA4 and SWR1 complexes, not only confirmed the PfNuA4 complex but also identified the PfSWR1 complex, a histone remodeling complex, although their identities are low compared to the homologs in yeast or humans. Notably, both H2A.Z/H2B.Z were associated with the PfSWR1 complex, indicating that this complex is involved in the deposition of H2A.Z/H2B.Z, the variant histone pair that is enriched in the activated promoters. Overexpression of PfMYST resulted in earlier expression of genes involved in cell cycle regulation, DNA replication, and merozoite invasion, and upregulation of the genes related to antigenic variation and DNA repair. Consistently, PfMYST overexpression led to high basal phosphorylated PfH2A (γ-PfH2A), the mark of DNA double-strand breaks, and conferred protection against genotoxic agent methyl methanesulfonate (MMS), X-rays, and artemisinin, the first-line antimalarial drug. In contrast, the knockdown of PfMYST caused a delayed parasite recovery upon MMS treatment. MMS induced the gradual disappearance of PfMYST in the cytoplasm and concomitant accumulation of PfMYST in the nucleus, suggesting cytoplasm-nucleus shuttling of PfMYST. Meanwhile, PfMYST colocalized with the γ-PfH2A, indicating PfMYST was recruited to the DNA damage sites. Collectively, PfMYST plays critical roles in cell cycle regulation, gene transcription, and DNA replication/DNA repair in this low-branching parasitic protist.IMPORTANCEUnderstanding gene regulation and DNA repair in malaria parasites is critical for identifying targets for antimalarials. This study found PfNuA4, a PfMYST-associated, histone modifier complex, and PfSWR1, a chromatin remodeling complex in malaria parasite Plasmodium falciparum. These complexes are divergent due to the low identities compared to their homologs from yeast and humans. Furthermore, overexpression of PfMYST resulted in substantial transcriptomic changes, indicating that PfMYST is involved in regulating the cell cycle, antigenic variation, and DNA replication/repair. Consistently, PfMYST was found to protect against DNA damage caused by the genotoxic agent methyl methanesulfonate, X-rays, and artemisinin, the first-line antimalarial drug. Additionally, DNA damage led to the relocation of cytoplasmic PfMYST to the nucleus and colocalization of PfMYST with γ-PfH2A, the mark of DNA damage. In summary, this study demonstrated that the PfMYST complex has critical functions in regulating cell cycle, antigenic variation, and DNA replication/DNA repair in P. falciparum.
Collapse
Affiliation(s)
- Mohammad Kalamuddin
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
| | - Ahmad Rushdi Shakri
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Hui Min
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
| | - Xiaolian Li
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Jun Miao
- Department of Internal Medicine, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| |
Collapse
|
3
|
Azizan S, Selvarajah SA, Tang J, Jeninga MD, Schulz D, Pareek K, Herr T, Day KP, De Koning-Ward TF, Petter M, Duffy MF. The P. falciparum alternative histones Pf H2A.Z and Pf H2B.Z are dynamically acetylated and antagonized by PfSir2 histone deacetylases at heterochromatin boundaries. mBio 2023; 14:e0201423. [PMID: 37882786 PMCID: PMC10746207 DOI: 10.1128/mbio.02014-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/18/2023] [Indexed: 10/27/2023] Open
Abstract
The Plasmodium falciparum alternative histones Pf H2A.Z and Pf H2B.Z are enriched in the same nucleosomes in intergenic euchromatin but depleted from heterochromatin. They occupy most promoters but are only dynamically associated with expression at var genes. In other organisms, acetylation of H2A.Z is important for its functions in gene expression and chromatin structure. Here, we show that acetylated Pf H2A.Z and Pf H2B.Z are dynamically associated with gene expression at promoters. In addition, acetylated Pf H2A.Z and Pf H2B.Z are antagonized by the sirtuin class III histone deacetylases (HDAC) PfSir2A and B at heterochromatin boundaries and encroach upon heterochromatin in parasites lacking PfSir2A or B. However, the majority of acetylated Pf H2A.Z and Pf H2B.Z are deacetylated by class I or II HDACs. Acetylated Pf H2A.Z and Pf H2B.Z are also dynamically associated with promoter activity of both canonical upstream var gene promoters and var gene introns. These findings suggest that both acetylated Pf H2A.Z and Pf H2B.Z play critical roles in gene expression and contribute to maintenance of chromatin structure at the boundaries of subtelomeric, facultative heterochromatin, critical for the variegated expression of genes that enable rapid adaptation to altered host environments.IMPORTANCEThe malaria parasite Plasmodium falciparum relies on variant expression of members of multi-gene families as a strategy for environmental adaptation to promote parasite survival and pathogenesis. These genes are located in transcriptionally silenced DNA regions. A limited number of these genes escape gene silencing, and switching between them confers variant fitness on parasite progeny. Here, we show that PfSir2 histone deacetylases antagonize DNA-interacting acetylated alternative histones at the boundaries between active and silent DNA. This finding implicates acetylated alternative histones in the mechanism regulating P. falciparum variant gene silencing and thus malaria pathogenesis. This work also revealed that acetylation of alternative histones at promoters is dynamically associated with promoter activity across the genome, implicating acetylation of alternative histones in gene regulation genome wide. Understanding mechanisms of gene regulation in P. falciparum may aid in the development of new therapeutic strategies for malaria, which killed 619,000 people in 2021.
Collapse
Affiliation(s)
- Suffian Azizan
- School of BioSciences, The University of Melbourne, Melbourne, Australia
- Bio21 Institute, Parkville, Victoria, Australia
| | - Shamista A. Selvarajah
- School of BioSciences, The University of Melbourne, Melbourne, Australia
- Bio21 Institute, Parkville, Victoria, Australia
| | - Jingyi Tang
- School of Medicine, Faculty of Health, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Australia
| | - Myriam D. Jeninga
- Universitätsklinikum Erlangen, Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | | | - Kapil Pareek
- Universitätsklinikum Erlangen, Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Tamara Herr
- Universitätsklinikum Erlangen, Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Karen P. Day
- Bio21 Institute, Parkville, Victoria, Australia
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Tania F. De Koning-Ward
- School of Medicine, Faculty of Health, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Australia
| | - Michaela Petter
- Universitätsklinikum Erlangen, Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Michael F. Duffy
- Bio21 Institute, Parkville, Victoria, Australia
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
4
|
Abstract
In eukaryotic organisms, noncoding RNAs (ncRNAs) have been implicated as important regulators of multifaceted biological processes, including transcriptional, posttranscriptional, and epigenetic regulation of gene expression. In recent years, it is becoming clear that protozoan parasites encode diverse ncRNA transcripts; however, little is known about their cellular functions. Recent advances in high-throughput “omic” studies identified many novel long ncRNAs (lncRNAs) in apicomplexan parasites, some of which undergo splicing, polyadenylation, and encode small proteins. To date, only a few of them are characterized, leaving a big gap in our understanding regarding their origin, mode of action, and functions in parasite biology. In this review, we focus on lncRNAs of the human malaria parasite Plasmodium falciparum and highlight their cellular functions and possible mechanisms of action.
Collapse
Affiliation(s)
- Karina Simantov
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Manish Goyal
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ron Dzikowski
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
5
|
Iyer U, Park JE, Sze SK, Bozdech Z, Featherstone M. Mediator Complex of the Malaria Parasite Plasmodium falciparum Associates with Evolutionarily Novel Subunits. ACS OMEGA 2022; 7:14867-14874. [PMID: 35557691 PMCID: PMC9088918 DOI: 10.1021/acsomega.2c00368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
The eukaryotic Mediator is a large and conserved multisubunit protein complex that directly contacts RNA polymerase II and impinges on multiple aspects of gene expression. The genome of the human malaria parasite Plasmodium falciparum has been predicted to encode several Mediator subunits. We provide physical evidence for the presence of a Mediator complex in P. falciparum by using coimmunoprecipitation and mass spectrometry to identify interaction partners of the highly conserved Mediator subunit PfMed31. We identify 11 of 14 predicted Mediator subunits and the products of two uncharacterized genes, PF3D7_0526800 and PF3D7_1363600, which are strongly associated with PfMed31. As expected, several additional interaction partners have known roles in the transcriptional control of gene expression and mRNA processing. Intriguingly, multiple interaction partners are implicated in endoplasmic reticulum function and the ER stress (ERS) response, suggesting crosstalk between the ERS response and the transcriptional machinery. Our results establish for the first time the physical presence of the Mediator complex within P. falciparum and strongly suggest that it plays both conserved and unique roles in the control of gene expression. Data are available via ProteomeXchange with the identifier PXD027640.
Collapse
|
6
|
Rawat M, Kanyal A, Choubey D, Deshmukh B, Malhotra R, Mamatharani DV, Rao AG, Karmodiya K. Identification of Co-Existing Mutations and Gene Expression Trends Associated With K13-Mediated Artemisinin Resistance in Plasmodium falciparum. Front Genet 2022; 13:824483. [PMID: 35464842 PMCID: PMC9019836 DOI: 10.3389/fgene.2022.824483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/08/2022] [Indexed: 11/13/2022] Open
Abstract
Plasmodium falciparum infects millions and kills thousands of people annually the world over. With the emergence of artemisinin and/or multidrug resistant strains of the pathogen, it has become even more challenging to control and eliminate the disease. Multiomics studies of the parasite have started to provide a glimpse into the confounding genetics and mechanisms of artemisinin resistance and identified mutations in Kelch13 (K13) as a molecular marker of resistance. Over the years, thousands of genomes and transcriptomes of artemisinin-resistant/sensitive isolates have been documented, supplementing the search for new genes/pathways to target artemisinin-resistant isolates. This meta-analysis seeks to recap the genetic landscape and the transcriptional deregulation that demarcate artemisinin resistance in the field. To explore the genetic territory of artemisinin resistance, we use genomic single-nucleotide polymorphism (SNP) datasets from 2,517 isolates from 15 countries from the MalariaGEN Network (The Pf3K project, pilot data release 4, 2015) to dissect the prevalence, geographical distribution, and co-existing patterns of genetic markers associated with/enabling artemisinin resistance. We have identified several mutations which co-exist with the established markers of artemisinin resistance. Interestingly, K13-resistant parasites harbor α-ß hydrolase and putative HECT domain-containing protein genes with the maximum number of SNPs. We have also explored the multiple, publicly available transcriptomic datasets to identify genes from key biological pathways whose consistent deregulation may be contributing to the biology of resistant parasites. Surprisingly, glycolytic and pentose phosphate pathways were consistently downregulated in artemisinin-resistant parasites. Thus, this meta-analysis highlights the genetic and transcriptomic features of resistant parasites to propel further exploratory studies in the community to tackle artemisinin resistance.
Collapse
Affiliation(s)
- Mukul Rawat
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Abhishek Kanyal
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Deepak Choubey
- Life Science Research Unit, Persistent Systems Limited, Pune, India
| | - Bhagyashree Deshmukh
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Rashim Malhotra
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - D V Mamatharani
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Anjani Gopal Rao
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Krishanpal Karmodiya
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| |
Collapse
|
7
|
Tintó-Font E, Cortés A. Malaria parasites do respond to heat. Trends Parasitol 2022; 38:435-449. [PMID: 35301987 DOI: 10.1016/j.pt.2022.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 01/09/2023]
Abstract
The capacity of malaria parasites to respond to changes in their environment at the transcriptional level has been the subject of debate, but recent evidence has unambiguously demonstrated that Plasmodium spp. can produce adaptive transcriptional responses when exposed to some specific types of stress. These include metabolic conditions and febrile temperature. The Plasmodium falciparum protective response to thermal stress is similar to the response in other organisms, but it is regulated by a transcription factor evolutionarily unrelated to the conserved transcription factor that drives the heat shock (HS) response in most eukaryotes. Of the many genes that change expression during HS, only a subset constitutes an authentic response that contributes to parasite survival.
Collapse
Affiliation(s)
- Elisabet Tintó-Font
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
| | - Alfred Cortés
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona 08036, Catalonia, Spain; ICREA, Barcelona 08010, Catalonia, Spain.
| |
Collapse
|
8
|
Dumetz F, Chow EYC, Harris LM, Liew SW, Jensen A, Umar MI, Chung B, Chan TF, Merrick CJ, Kwok CK. G-quadruplex RNA motifs influence gene expression in the malaria parasite Plasmodium falciparum. Nucleic Acids Res 2021; 49:12486-12501. [PMID: 34792144 PMCID: PMC8643661 DOI: 10.1093/nar/gkab1095] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 11/12/2022] Open
Abstract
G-quadruplexes are non-helical secondary structures that can fold in vivo in both DNA and RNA. In human cells, they can influence replication, transcription and telomere maintenance in DNA, or translation, transcript processing and stability of RNA. We have previously showed that G-quadruplexes are detectable in the DNA of the malaria parasite Plasmodium falciparum, despite a very highly A/T-biased genome with unusually few guanine-rich sequences. Here, we show that RNA G-quadruplexes can also form in P. falciparum RNA, using rG4-seq for transcriptome-wide structure-specific RNA probing. Many of the motifs, detected here via the rG4seeker pipeline, have non-canonical forms and would not be predicted by standard in silico algorithms. However, in vitro biophysical assays verified formation of non-canonical motifs. The G-quadruplexes in the P. falciparum transcriptome are frequently clustered in certain genes and associated with regions encoding low-complexity peptide repeats. They are overrepresented in particular classes of genes, notably those that encode PfEMP1 virulence factors, stress response genes and DNA binding proteins. In vitro translation experiments and in vivo measures of translation efficiency showed that G-quadruplexes can influence the translation of P. falciparum mRNAs. Thus, the G-quadruplex is a novel player in post-transcriptional regulation of gene expression in this major human pathogen.
Collapse
Affiliation(s)
- Franck Dumetz
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Eugene Yui-Ching Chow
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Lynne M Harris
- Centre for Applied Entomology and Parasitology, Faculty of Natural Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK
| | - Shiau Wei Liew
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Anders Jensen
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Mubarak I Umar
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Betty Chung
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Ting Fung Chan
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Catherine J Merrick
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|
9
|
Zanghi G, Vaughan AM. Plasmodium vivax pre-erythrocytic stages and the latent hypnozoite. Parasitol Int 2021; 85:102447. [PMID: 34474178 DOI: 10.1016/j.parint.2021.102447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 02/02/2023]
Abstract
Plasmodium vivax is the most geographically widespread malaria parasite on the planet. This is largely because after mosquito transmission, P. vivax sporozoites can invade hepatocytes and form latent liver stages known as hypnozoites. These persistent liver stages can activate weeks, months or even years after an infected individual suffers a primary clinical infection. Activation then leads to replication and liver stage schizont maturation that ultimately cause relapse of blood stage infection, disease, and onward transmission. Thus, the latent hypnozoite can lie in wait during times when onward transmission is unlikely due to conditions that do not favor the mosquito. For example, in temperate climates where mosquito prevalence is only seasonal. Furthermore, the elimination of hypnozoites is challenging since the hypnozoite reservoir is currently undetectable and not killed by most antimalarial drugs. Here, we review our current knowledge of the pre-erythrocytic stages of the malaria parasite - the sporozoite and liver stages, including the elusive and enigmatic hypnozoite. We focus on our understanding of sporozoite biology, the novel animal models that are available to study the hypnozoite and hypnozoite activation and the ongoing efforts to understand the biological makeup of the hypnozoite that allow for its persistence in the human host.
Collapse
Affiliation(s)
| | - Ashley M Vaughan
- Seattle Children's Research Institute, Seattle, WA, USA; Department of Pediatrics, University of Washington, Seattle, WA, USA.
| |
Collapse
|
10
|
Ngwa CJ, Farrukh A, Pradel G. Zinc finger proteins of Plasmodium falciparum. Cell Microbiol 2021; 23:e13387. [PMID: 34418264 DOI: 10.1111/cmi.13387] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 01/14/2023]
Abstract
Zinc finger proteins (ZFPs) are a large diverse family of proteins with one or more zinc finger domains in which zinc is important in stabilising the domain. ZFPs can interact with DNA, RNA, lipids or even other proteins and therefore contribute to diverse cellular processes including transcriptional regulation, ubiquitin-mediated protein degradation, mRNA decay and stability. In this review, we provide the first comprehensive classification of ZFPs of the malaria parasite Plasmodium falciparum and provide a state of knowledge on the main ZFPs in the parasite, which include the C2H2, CCCH, RING finger and the PHD finger proteins. TAKE AWAYS: The Plasmodium falciparum genome encodes 170 putative Zinc finger proteins (ZFPs). The C2H2, CCCH, RING finger and PHD finger subfamilies of ZFPs are most represented. Known ZFP functions include the regulation of mRNA metabolism and proteostasis.
Collapse
Affiliation(s)
- Che Julius Ngwa
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Afia Farrukh
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| |
Collapse
|
11
|
Miao J, Wang C, Lucky AB, Liang X, Min H, Adapa SR, Jiang R, Kim K, Cui L. A unique GCN5 histone acetyltransferase complex controls erythrocyte invasion and virulence in the malaria parasite Plasmodium falciparum. PLoS Pathog 2021; 17:e1009351. [PMID: 34403450 PMCID: PMC8396726 DOI: 10.1371/journal.ppat.1009351] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 08/27/2021] [Accepted: 07/21/2021] [Indexed: 12/14/2022] Open
Abstract
The histone acetyltransferase GCN5-associated SAGA complex is evolutionarily conserved from yeast to human and functions as a general transcription co-activator in global gene regulation. In this study, we identified a divergent GCN5 complex in Plasmodium falciparum, which contains two plant homeodomain (PHD) proteins (PfPHD1 and PfPHD2) and a plant apetela2 (AP2)-domain transcription factor (PfAP2-LT). To dissect the functions of the PfGCN5 complex, we generated parasite lines with either the bromodomain in PfGCN5 or the PHD domain in PfPHD1 deleted. The two deletion mutants closely phenocopied each other, exhibiting significantly reduced merozoite invasion of erythrocytes and elevated sexual conversion. These domain deletions caused dramatic decreases not only in histone H3K9 acetylation but also in H3K4 trimethylation, indicating synergistic crosstalk between the two euchromatin marks. Domain deletion in either PfGCN5 or PfPHD1 profoundly disturbed the global transcription pattern, causing altered expression of more than 60% of the genes. At the schizont stage, these domain deletions were linked to specific down-regulation of merozoite genes involved in erythrocyte invasion, many of which contain the AP2-LT binding motif and are also regulated by AP2-I and BDP1, suggesting targeted recruitment of the PfGCN5 complex to the invasion genes by these specific factors. Conversely, at the ring stage, PfGCN5 or PfPHD1 domain deletions disrupted the mutually exclusive expression pattern of the entire var gene family, which encodes the virulent factor PfEMP1. Correlation analysis between the chromatin state and alteration of gene expression demonstrated that up- and down-regulated genes in these mutants are highly correlated with the silent and active chromatin states in the wild-type parasite, respectively. Collectively, the PfGCN5 complex represents a novel HAT complex with a unique subunit composition including an AP2 transcription factor, which signifies a new paradigm for targeting the co-activator complex to regulate general and parasite-specific cellular processes in this low-branching parasitic protist. Epigenetic regulation of gene expression plays essential roles in orchestrating the general and parasite-specific cellular pathways in the malaria parasite Plasmodium falciparum. To better understand the epigenetic mechanisms in this parasite, we characterized the histone acetyltransferase GCN5-mediated transcription regulation during intraerythrocytic development of the parasite. Using tandem affinity purification and proteomic characterization, we identified that the PfGCN5-associated complex contains nine core components, including two PHD domain proteins (PfPHD1 and PfPHD2) and an AP2-domain transcription factor, which is divergent from the canonical GCN5 complexes evolutionarily conserved from yeast to human. To understand the functions of the PfGCN5 complex, we performed domain deletions in two subunits of this complex, PfGCN5 and PfPHD1. We found that the two deletion mutants displayed very similar growth phenotypes, including significantly reduced merozoite invasion rates and elevated sexual conversion. These two mutants were associated with dramatic decreases in histone H3K9 acetylation and H3K4 trimethylation, which led to global changes in chromatin states and gene expression. Consistent with the phenotypes, genes significantly affected by the PfGCN5 and PfPHD1 gene disruption include those participating in parasite-specific pathways such as invasion, virulence, and sexual development. In conclusion, this study presents a new model of the PfGCN5 complex for targeting the co-activator complex to regulate general and parasite-specific cellular processes in this low-branching parasitic protist.
Collapse
Affiliation(s)
- Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
- * E-mail: (JM); (LC)
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Amuza Byaruhanga Lucky
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Xiaoying Liang
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Hui Min
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Swamy Rakesh Adapa
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Rays Jiang
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Kami Kim
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
- * E-mail: (JM); (LC)
| |
Collapse
|
12
|
Peculiarities of Plasmodium falciparum Gene Regulation and Chromatin Structure. Int J Mol Sci 2021; 22:ijms22105168. [PMID: 34068393 PMCID: PMC8153576 DOI: 10.3390/ijms22105168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022] Open
Abstract
The highly complex life cycle of the human malaria parasite, Plasmodium falciparum, is based on an orchestrated and tightly regulated gene expression program. In general, eukaryotic transcription regulation is determined by a combination of sequence-specific transcription factors binding to regulatory DNA elements and the packaging of DNA into chromatin as an additional layer. The accessibility of regulatory DNA elements is controlled by the nucleosome occupancy and changes of their positions by an active process called nucleosome remodeling. These epigenetic mechanisms are poorly explored in P. falciparum. The parasite genome is characterized by an extraordinarily high AT-content and the distinct architecture of functional elements, and chromatin-related proteins also exhibit high sequence divergence compared to other eukaryotes. Together with the distinct biochemical properties of nucleosomes, these features suggest substantial differences in chromatin-dependent regulation. Here, we highlight the peculiarities of epigenetic mechanisms in P. falciparum, addressing chromatin structure and dynamics with respect to their impact on transcriptional control. We focus on the specialized chromatin remodeling enzymes and discuss their essential function in P. falciparum gene regulation.
Collapse
|
13
|
Singh S, Santos JM, Orchard LM, Yamada N, van Biljon R, Painter HJ, Mahony S, Llinás M. The PfAP2-G2 transcription factor is a critical regulator of gametocyte maturation. Mol Microbiol 2021; 115:1005-1024. [PMID: 33368818 PMCID: PMC8330521 DOI: 10.1111/mmi.14676] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 12/14/2022]
Abstract
Differentiation from asexual blood stages to mature sexual gametocytes is required for the transmission of malaria parasites. Here, we report that the ApiAP2 transcription factor, PfAP2-G2 (PF3D7_1408200) plays a critical role in the maturation of Plasmodium falciparum gametocytes. PfAP2-G2 binds to the promoters of a wide array of genes that are expressed at many stages of the parasite life cycle. Interestingly, we also find binding of PfAP2-G2 within the gene body of almost 3,000 genes, which strongly correlates with the location of H3K36me3 and several other histone modifications as well as Heterochromatin Protein 1 (HP1), suggesting that occupancy of PfAP2-G2 in gene bodies may serve as an alternative regulatory mechanism. Disruption of pfap2-g2 does not impact asexual development, but the majority of sexual parasites are unable to mature beyond stage III gametocytes. The absence of pfap2-g2 leads to overexpression of 28% of the genes bound by PfAP2-G2 and none of the PfAP2-G2 bound genes are downregulated, suggesting that it is a repressor. We also find that PfAP2-G2 interacts with chromatin remodeling proteins, a microrchidia (MORC) protein, and another ApiAP2 protein (PF3D7_1139300). Overall our data demonstrate that PfAP2-G2 establishes an essential gametocyte maturation program in association with other chromatin-related proteins.
Collapse
Affiliation(s)
- Suprita Singh
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
| | - Joana M. Santos
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
| | - Lindsey M. Orchard
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
| | - Naomi Yamada
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA 16802
| | - Riëtte van Biljon
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
| | - Heather J. Painter
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
| | - Shaun Mahony
- Center for Eukaryotic Gene Regulation, Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802, Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA 16802
- Center for Eukaryotic Gene Regulation, Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, USA 16802
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA 16802
| |
Collapse
|
14
|
Menichelli C, Guitard V, Martins RM, Lèbre S, Lopez-Rubio JJ, Lecellier CH, Bréhélin L. Identification of long regulatory elements in the genome of Plasmodium falciparum and other eukaryotes. PLoS Comput Biol 2021; 17:e1008909. [PMID: 33861755 PMCID: PMC8081344 DOI: 10.1371/journal.pcbi.1008909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 04/28/2021] [Accepted: 03/24/2021] [Indexed: 01/15/2023] Open
Abstract
Long regulatory elements (LREs), such as CpG islands, polydA:dT tracts or AU-rich elements, are thought to play key roles in gene regulation but, as opposed to conventional binding sites of transcription factors, few methods have been proposed to formally and automatically characterize them. We present here a computational approach named DExTER (Domain Exploration To Explain gene Regulation) dedicated to the identification of candidate LREs (cLREs) and apply it to the analysis of the genomes of P. falciparum and other eukaryotes. Our analyses show that all tested genomes contain several cLREs that are somewhat conserved along evolution, and that gene expression can be predicted with surprising accuracy on the basis of these long regions only. Regulation by cLREs exhibits very different behaviours depending on species and conditions. In P. falciparum and other Apicomplexan organisms as well as in Dictyostelium discoideum, the process appears highly dynamic, with different cLREs involved at different phases of the life cycle. For multicellular organisms, the same cLREs are involved in all tissues, but a dynamic behavior is observed along embryonic development stages. In P. falciparum, whose genome is known to be strongly depleted of transcription factors, cLREs are predictive of expression with an accuracy above 70%, and our analyses show that they are associated with both transcriptional and post-transcriptional regulation signals. Moreover, we assessed the biological relevance of one LRE discovered by DExTER in P. falciparum using an in vivo reporter assay. The source code (python) of DExTER is available at https://gite.lirmm.fr/menichelli/DExTER.
Collapse
Affiliation(s)
| | - Vincent Guitard
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Rafael M. Martins
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Sophie Lèbre
- IMAG, Univ. Montpellier, CNRS, Montpellier, France
- Univ. Paul-Valéry-Montpellier 3, Montpellier, France
| | - Jose-Juan Lopez-Rubio
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Charles-Henri Lecellier
- LIRMM, Univ Montpellier, CNRS, Montpellier, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | | |
Collapse
|
15
|
Xu Y, Qiao D, Wen Y, Bi Y, Chen Y, Huang Z, Cui L, Guo J, Cao Y. PfAP2-G2 Is Associated to Production and Maturation of Gametocytes in Plasmodium falciparum via Regulating the Expression of PfMDV-1. Front Microbiol 2021; 11:631444. [PMID: 33537025 PMCID: PMC7848025 DOI: 10.3389/fmicb.2020.631444] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
Gametocyte is the sole form of the Plasmodium falciparum which is transmissible to the mosquito vector. Here, we report that an Apicomplexan Apetala2 (ApiAP2) family transcription factor, PfAP2-G2 (Pf3D7_1408200), plays a role in the development of gametocytes in P. falciparum by regulating the expression of PfMDV-1 (Pf3D7_1216500). Reverse transcriptase-quantitative PCR (RT-qPCR) analysis showed that PfAP2-G2 was highly expressed in the ring stage. Indirect immunofluorescence assay showed nuclear localization of PfAP2-G2 in asexual stages. The knockout of PfAP2-G2 led to a ~95% decrease in the number of mature gametocytes with a more substantial influence on the production and maturation of the male gametocytes, resulting in a higher female/male gametocyte ratio. To test the mechanism of this phenotype, RNA-seq and RT-qPCR showed that disruption of PfAP2-G2 led to the down-regulation of male development gene-1 (PfMDV-1) in asexual stages. We further found that PfAP2-G2 was enriched at the transcriptional start site (TSS) of PfMDV-1 by chromatin immunoprecipitation and qPCR assay in both ring stage and schizont stage, which demonstrated that PfMDV-1 is one of the targets of PfAP2-G2. In addition, RT-qPCR also showed that PfAP2-G (Pf3D7_1222600), the master regulator for sexual commitment, was also down-regulated in the PfAP2-G2 knockout parasites in the schizont stage, but no change in the ring stage. This phenomenon suggested that PfAP2-G2 played a role at the asexual stage for the development of parasite gametocytes and warrants further investigations in regulatory pathways of PfAP2-G2.
Collapse
Affiliation(s)
- Yaozheng Xu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Dan Qiao
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuhao Wen
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Yifei Bi
- Philosophy, Politics and Economics Department, University College London, London, United Kingdom
| | - Yuxi Chen
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Zhenghui Huang
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Jian Guo
- Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| |
Collapse
|
16
|
Briquet S, Marinach C, Silvie O, Vaquero C. Preparing for Transmission: Gene Regulation in Plasmodium Sporozoites. Front Cell Infect Microbiol 2021; 10:618430. [PMID: 33585284 PMCID: PMC7878544 DOI: 10.3389/fcimb.2020.618430] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/16/2020] [Indexed: 11/13/2022] Open
Abstract
Plasmodium sporozoites are transmitted to mammals by anopheline mosquitoes and first infect the liver, where they transform into replicative exoerythrocytic forms, which subsequently release thousands of merozoites that invade erythrocytes and initiate the malaria disease. In some species, sporozoites can transform into dormant hypnozoites in the liver, which cause malaria relapses upon reactivation. Transmission from the insect vector to a mammalian host is a critical step of the parasite life cycle, and requires tightly regulated gene expression. Sporozoites are formed inside oocysts in the mosquito midgut and become fully infectious after colonization of the insect salivary glands, where they remain quiescent until transmission. Parasite maturation into infectious sporozoites is associated with reprogramming of the sporozoite transcriptome and proteome, which depends on multiple layers of transcriptional and post-transcriptional regulatory mechanisms. An emerging scheme is that gene expression in Plasmodium sporozoites is controlled by alternating waves of transcription activity and translational repression, which shape the parasite RNA and protein repertoires for successful transition from the mosquito vector to the mammalian host.
Collapse
Affiliation(s)
- Sylvie Briquet
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Carine Marinach
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Olivier Silvie
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Catherine Vaquero
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| |
Collapse
|
17
|
Neal ML, Wei L, Peterson E, Arrieta-Ortiz ML, Danziger S, Baliga N, Kaushansky A, Aitchison J. A systems-level gene regulatory network model for Plasmodium falciparum. Nucleic Acids Res 2021; 49:4891-4906. [PMID: 33450011 PMCID: PMC8136813 DOI: 10.1093/nar/gkaa1245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/26/2020] [Accepted: 01/06/2021] [Indexed: 12/30/2022] Open
Abstract
Many of the gene regulatory processes of Plasmodium falciparum, the deadliest malaria parasite, remain poorly understood. To develop a comprehensive guide for exploring this organism's gene regulatory network, we generated a systems-level model of P. falciparum gene regulation using a well-validated, machine-learning approach for predicting interactions between transcription regulators and their targets. The resulting network accurately predicts expression levels of transcriptionally coherent gene regulatory programs in independent transcriptomic data sets from parasites collected by different research groups in diverse laboratory and field settings. Thus, our results indicate that our gene regulatory model has predictive power and utility as a hypothesis-generating tool for illuminating clinically relevant gene regulatory mechanisms within P. falciparum. Using the set of regulatory programs we identified, we also investigated correlates of artemisinin resistance based on gene expression coherence. We report that resistance is associated with incoherent expression across many regulatory programs, including those controlling genes associated with erythrocyte-host engagement. These results suggest that parasite populations with reduced artemisinin sensitivity are more transcriptionally heterogenous. This pattern is consistent with a model where the parasite utilizes bet-hedging strategies to diversify the population, rendering a subpopulation more able to navigate drug treatment.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - John D Aitchison
- To whom correspondence should be addressed. Tel: +1 206 884 3125; Fax: +1 206 884 3104;
| |
Collapse
|
18
|
Merrick CJ. Hypnozoites in Plasmodium: Do Parasites Parallel Plants? Trends Parasitol 2020; 37:273-282. [PMID: 33257270 DOI: 10.1016/j.pt.2020.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022]
Abstract
The phenomenon of relapsing malaria has been recognised for centuries. It is caused in humans by the parasite species Plasmodium vivax and Plasmodium ovale, which can arrest growth at an early, asymptomatic stage as hypnozoites inside liver cells. These dormant parasites can remain quiescent for months or years, then reactivate causing symptomatic malaria. The dynamics of hypnozoite dormancy and reactivation are well documented but the molecular basis remains a complete mystery. Here, I observe that the process has striking parallels with plant vernalisation, whereby plants remain dormant through the winter before flowering in spring. Vernalisation is thoroughly studied in several plant species and its mechanisms are known in exquisite detail. Vernalisation may thus provide a useful framework for interrogating hypnozoite biology.
Collapse
Affiliation(s)
- Catherine J Merrick
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, CB2 1QP, UK.
| |
Collapse
|
19
|
Govindaraju G, Kadumuri RV, Sethumadhavan DV, Jabeena CA, Chavali S, Rajavelu A. N 6-Adenosine methylation on mRNA is recognized by YTH2 domain protein of human malaria parasite Plasmodium falciparum. Epigenetics Chromatin 2020; 13:33. [PMID: 32867812 PMCID: PMC7457798 DOI: 10.1186/s13072-020-00355-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/18/2020] [Indexed: 12/30/2022] Open
Abstract
Background Plasmodium falciparum exhibits high translational plasticity during its development in RBCs, yet the regulation at the post-transcriptional level is not well understood. The N6-methyl adenosine (m6A) is an important epigenetic modification primarily present on mRNA that controls the levels of transcripts and efficiency of translation in eukaryotes. Recently, the dynamics of m6A on mRNAs at all three developmental stages of P. falciparum in RBCs have been profiled; however, the proteins that regulate the m6A containing mRNAs in the parasites are unknown. Results Using sequence analysis, we computationally identified that the P. falciparum genome encodes two putative YTH (YT521-B Homology) domain-containing proteins, which could potentially bind to m6A containing mRNA. We developed a modified methylated RNA immunoprecipitation (MeRIP) assay using PfYTH2 and find that it binds selectively to m6A containing transcripts. The PfYTH2 has a conserved aromatic amino acid cage that forms the methyl-binding pocket. Through site-directed mutagenesis experiments and molecular dynamics simulations, we show that F98 residue is important for m6A binding on mRNA. Fluorescence depolarization assay confirmed that PfYTH2 binds to methylated RNA oligos with high affinity. Further, MeRIP sequencing data revealed that PfYTH2 has more permissive sequence specificity on target m6A containing mRNA than other known eukaryotic YTH proteins. Taken together, here we identify and characterize PfYTH2 as the major protein that could regulate m6A containing transcripts in P. falciparum. Conclusion Plasmodium spp. lost the canonical m6A-specific demethylases in their genomes, however, the YTH domain-containing proteins seem to be retained. This study presents a possibility that the YTH proteins are involved in post-transcriptional control in P. falciparum, and might orchestrate the translation of mRNA in various developmental stages of P. falciparum. This is perhaps the first characterization of the methyl-reading function of YTH protein in any parasites.
Collapse
Affiliation(s)
- Gayathri Govindaraju
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram, Kerala, 695014, India.,Manipal Academy of Higher Education, Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Rajashekar Varma Kadumuri
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Karakambadi Road, Tirupati, Andhra Pradesh, 517507, India
| | - Devadathan Valiyamangalath Sethumadhavan
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram, Kerala, 695014, India.,Manipal Academy of Higher Education, Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - C A Jabeena
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram, Kerala, 695014, India.,Manipal Academy of Higher Education, Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Sreenivas Chavali
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Karakambadi Road, Tirupati, Andhra Pradesh, 517507, India
| | - Arumugam Rajavelu
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram, Kerala, 695014, India.
| |
Collapse
|
20
|
Parra-Marín O, López-Pacheco K, Hernández R, López-Villaseñor I. The highly diverse TATA box-binding proteins among protists: A review. Mol Biochem Parasitol 2020; 239:111312. [PMID: 32771681 DOI: 10.1016/j.molbiopara.2020.111312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/28/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Transcription is the first step of gene expression regulation and is a fundamental mechanism for establishing the viability and development of a cell. The TATA box-binding protein (TBP) interaction with a TATA box in a promoter is one of the best studied mechanisms in transcription initiation. TBP is a transcription factor that is highly conserved from archaea to humans and is essential for the transcription initiated by each of the three RNA polymerases. In addition, the discovery of TBP-related factor 1 (TRF1) and other factors related to TBP shed light on the variability among transcription initiation complexes, thus demonstrating that the compositions of these complexes are, in fact, more complicated than originally believed. Despite these facts, the majority of studies on transcription have been performed on animal, plant and fungal cells, which serve as canonical models, and information regarding protist cells is relatively scarce. The aim of this work is to review the diversity of the TBPs that have been documented in protists and describe some of the specific features that differentiate them from their counterparts in higher eukaryotes.
Collapse
Affiliation(s)
- Olivia Parra-Marín
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Ciudad de México, Mexico
| | - Karla López-Pacheco
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Ciudad de México, Mexico
| | - Roberto Hernández
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Ciudad de México, Mexico
| | - Imelda López-Villaseñor
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Ciudad de México, Mexico.
| |
Collapse
|
21
|
Wang WF, Zhang YL. PfSWIB, a potential chromatin regulator for var gene regulation and parasite development in Plasmodium falciparum. Parasit Vectors 2020; 13:48. [PMID: 32019597 PMCID: PMC7001229 DOI: 10.1186/s13071-020-3918-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 01/29/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Various transcription factors are involved in the process of mutually exclusive expression and clonal variation of the Plasmodium multigene (var) family. Recent studies revealed that a P. falciparum SWI/SNF-related matrix-associated actin-dependent regulator of chromatin (PfSWIB) might trigger stage-specific programmed cell death (PCD), and was not only crucial for the survival and development of parasite, but also had profound effects on the parasite by interacting with other unknown proteins. However, it remains unclear whether PfSIWB is involved in transcriptional regulation of this virulence gene and its functional properties. METHODS A conditional knockdown system "PfSWIB-FKBP-LID" was introduced to the parasite clone 3D7, and an integrated parasite line "PfSWIB-HA-FKBP-LID" was obtained by drug cycling and clone screening. Growth curve analysis (GCA) was performed to investigate the growth and development of different parasite lines during 96 h in vitro culturing, by assessing parasitemia. Finally, we performed qPCR assays to detect var gene expression profiling in various comparison groups, as well as the mutually exclusive expression pattern of the var genes within a single 48 h life-cycle of P. falciparum in different parasite lines. In addition, RNA-seq was applied to analyze the var gene expression in different lines. RESULTS GCA revealed that conditional knockdown of PfSWIB could interfere with the growth and development of P. falciparum. The parasitemia of PfSWIB∆ showed a significant decline at 96 h during in vitro culture compared with the PfSWIB and 3D7 lines (P < 0.0001). qPCR and RNA-seq analysis confirmed that depletion of PfSWIB not only silences upsA, upsC and partial upsB var genes, as well as removes the silencing of partial upsB var genes at the ring stage in PfSWIB∆ line, but also leads to aberrant expression of upsA and partial upsB/upsC var genes at the mature stage of P. falciparum, during a single 48-h life-cycle. CONCLUSIONS We demonstrated that PfSWIB was involved in the process of clonal variation in var gene expression, and crucial for the survival and development of Plasmodium parasite. These findings could provide better understanding of the mechanism and function of PfSWIB contributing to the pathogenesis in malaria parasites.
Collapse
Affiliation(s)
- Wei-Feng Wang
- Central Laboratory, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China.,Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, China
| | - Yi-Long Zhang
- Department of Tropical Diseases, Faculty of Naval Medicine, Second Military Medical University, Shanghai, 200433, China. .,Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, China.
| |
Collapse
|
22
|
Batugedara G, Lu XM, Saraf A, Sardiu ME, Cort A, Abel S, Prudhomme J, Washburn MP, Florens L, Bunnik EM, Le Roch KG. The chromatin bound proteome of the human malaria parasite. Microb Genom 2020; 6:e000327. [PMID: 32017676 PMCID: PMC7067212 DOI: 10.1099/mgen.0.000327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
Proteins interacting with DNA are fundamental for mediating processes such as gene expression, DNA replication and maintenance of genome integrity. Accumulating evidence suggests that the chromatin of apicomplexan parasites, such as Plasmodium falciparum, is highly organized, and this structure provides an epigenetic mechanism for transcriptional regulation. To investigate how parasite chromatin structure is being regulated, we undertook comparative genomics analysis using 12 distinct eukaryotic genomes. We identified conserved and parasite-specific chromatin-associated domains (CADs) and proteins (CAPs). We then used the chromatin enrichment for proteomics (ChEP) approach to experimentally capture CAPs in P. falciparum. A topological scoring analysis of the proteomics dataset revealed stage-specific enrichments of CADs and CAPs. Finally, we characterized, two candidate CAPs: a conserved homologue of the structural maintenance of chromosome 3 protein and a homologue of the crowded-like nuclei protein, a plant-like protein functionally analogous to animal nuclear lamina proteins. Collectively, our results provide a comprehensive overview of CAPs in apicomplexans, and contribute to our understanding of the complex molecular components regulating chromatin structure and genome architecture in these deadly parasites.
Collapse
Affiliation(s)
- Gayani Batugedara
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Xueqing M. Lu
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Anita Saraf
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA
| | - Mihaela E. Sardiu
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA
| | - Anthony Cort
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Steven Abel
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Jacques Prudhomme
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Michael P. Washburn
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA
| | - Evelien M. Bunnik
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Karine G. Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| |
Collapse
|
23
|
Toenhake CG, Bártfai R. What functional genomics has taught us about transcriptional regulation in malaria parasites. Brief Funct Genomics 2019; 18:290-301. [PMID: 31220867 PMCID: PMC6859821 DOI: 10.1093/bfgp/elz004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/08/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
Malaria parasites are characterized by a complex life cycle that is accompanied by dynamic gene expression patterns. The factors and mechanisms that regulate gene expression in these parasites have been searched for even before the advent of next generation sequencing technologies. Functional genomics approaches have substantially boosted this area of research and have yielded significant insights into the interplay between epigenetic, transcriptional and post-transcriptional mechanisms. Recently, considerable progress has been made in identifying sequence-specific transcription factors and DNA-encoded regulatory elements. Here, we review the insights obtained from these efforts including the characterization of core promoters, the involvement of sequence-specific transcription factors in life cycle progression and the mapping of gene regulatory elements. Furthermore, we discuss recent developments in the field of functional genomics and how they might contribute to further characterization of this complex gene regulatory network.
Collapse
Affiliation(s)
- Christa G Toenhake
- Radboud University, Faculty of Science, Department of Molecular Biology, Nijmegen, the Netherlands
| | - Richárd Bártfai
- Radboud University, Faculty of Science, Department of Molecular Biology, Nijmegen, the Netherlands
| |
Collapse
|
24
|
ApiAP2 Transcription Factors in Apicomplexan Parasites. Pathogens 2019; 8:pathogens8020047. [PMID: 30959972 PMCID: PMC6631176 DOI: 10.3390/pathogens8020047] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 12/26/2022] Open
Abstract
Apicomplexan parasites are protozoan organisms that are characterised by complex life cycles and they include medically important species, such as the malaria parasite Plasmodium and the causative agents of toxoplasmosis (Toxoplasma gondii) and cryptosporidiosis (Cryptosporidium spp.). Apicomplexan parasites can infect one or more hosts, in which they differentiate into several morphologically and metabolically distinct life cycle stages. These developmental transitions rely on changes in gene expression. In the last few years, the important roles of different members of the ApiAP2 transcription factor family in regulating life cycle transitions and other aspects of parasite biology have become apparent. Here, we review recent progress in our understanding of the different members of the ApiAP2 transcription factor family in apicomplexan parasites.
Collapse
|
25
|
Sardar R, Kaushik A, Pandey R, Mohmmed A, Ali S, Gupta D. ApicoTFdb: the comprehensive web repository of apicomplexan transcription factors and transcription-associated co-factors. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2019; 2019:5560306. [PMID: 31529106 PMCID: PMC6748703 DOI: 10.1093/database/baz094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/28/2019] [Accepted: 06/28/2019] [Indexed: 02/03/2023]
Abstract
Despite significant progress in apicomplexan genome sequencing and genomics, the current list of experimentally validated transcription factors (TFs) in these genomes is incomplete and mainly consists of AP2 family of proteins, with only a limited number of non-AP2 family TFs and transcription-associated co-factors (TcoFs). We have performed a systematic bioinformatics-aided prediction of TFs and TcoFs in apicomplexan genomes and developed the ApicoTFdb database which consists of experimentally validated as well as computationally predicted TFs and TcoFs in 14 apicomplexan species. The predicted TFs are manually curated to complement the existing annotations. The current version of the database includes 1292 TFs which includes experimentally validated and computationally predicted TFs, representing 20 distinct families across 14 apicomplexan species. The predictions include TFs of TUB, NAC, BSD, HTH, Cupin/Jumonji, winged helix and FHA family proteins, not reported earlier as TFs in the genomes. Apart from TFs, ApicoTFdb also classifies TcoFs into three main subclasses: TRs, CRRs and RNARs, representing 2491 TcoFs in 14 apicomplexan species, are analyzed in this study. The database is designed to integrate different tools for comparative analysis. All entries in the database are dynamically linked with other databases, literature reference, protein–protein interactions, pathways and annotations associated with each protein. ApicoTFdb will be useful to the researchers interested in less-studied gene regulatory mechanisms mediating the complex life cycle of the apicomplexan parasites. The database will aid in the discovery of novel drug targets to much needed combat the growing drug resistance in the parasites.
Collapse
Affiliation(s)
- Rahila Sardar
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.,Department of Biochemistry, Jamia Hamdard, Hamdard Nagar, New Delhi 110057, India
| | - Abhinav Kaushik
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Rajan Pandey
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Asif Mohmmed
- Parasite Cell Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shakir Ali
- Department of Biochemistry, Jamia Hamdard, Hamdard Nagar, New Delhi 110057, India
| | - Dinesh Gupta
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| |
Collapse
|
26
|
Briquet S, Ourimi A, Pionneau C, Bernardes J, Carbone A, Chardonnet S, Vaquero C. Identification of Plasmodium falciparum nuclear proteins by mass spectrometry and proposed protein annotation. PLoS One 2018; 13:e0205596. [PMID: 30379851 PMCID: PMC6209197 DOI: 10.1371/journal.pone.0205596] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 09/27/2018] [Indexed: 11/25/2022] Open
Abstract
The nuclear proteome of Plasmodium falciparum results from the continual shuttle of proteins between the cell cytoplasm-nucleus and vice versa. Using shotgun proteomics tools, we explored the nuclear proteins of mixed populations of Plasmodium falciparum extracted from infected erythrocytes. We combined GeLC-MS/MS and 2D-LC-MS/MS with a peptide ion exclusion procedure in order to increase the detection of low abundant proteins such as those involved in gene expression. We have identified 446 nuclear proteins covering all expected nuclear protein families involved in gene regulation. All structural ribosomal (40S and 60S) proteins were identified which is consistent with the nuclear localization of ribosomal biogenesis. Proteins involved in the translation machinery were also found suggesting that translational events might occur in the nucleus in P. falciparum as previously hypothesized in eukaryotes. These data were compared to the protein list established by PlasmoDB and submitted to Plasmobase a recently reported Plasmodium annotation website to propose new functional putative annotation of several unknown proteins found in the nuclear extracts.
Collapse
Affiliation(s)
- Sylvie Briquet
- Sorbonne Université, INSERM, CNRS, Centre d'immunologie et des maladies infectieuses, CIMI-Paris, Paris, France
| | - Asma Ourimi
- Sorbonne Université, INSERM, CNRS, Centre d'immunologie et des maladies infectieuses, CIMI-Paris, Paris, France
| | - Cédric Pionneau
- Sorbonne Université, INSERM, UMS Omique, Plateforme Post-génomique de la Pitié-Salpêtrière, Paris, France
| | - Juliana Bernardes
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 4 place Jussieu, Paris, France
| | - Alessandra Carbone
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 4 place Jussieu, Paris, France
- Institut Universitaire de France, Paris, France
| | - Solenne Chardonnet
- Sorbonne Université, INSERM, UMS Omique, Plateforme Post-génomique de la Pitié-Salpêtrière, Paris, France
| | - Catherine Vaquero
- Sorbonne Université, INSERM, CNRS, Centre d'immunologie et des maladies infectieuses, CIMI-Paris, Paris, France
| |
Collapse
|
27
|
Toenhake CG, Fraschka SAK, Vijayabaskar MS, Westhead DR, van Heeringen SJ, Bártfai R. Chromatin Accessibility-Based Characterization of the Gene Regulatory Network Underlying Plasmodium falciparum Blood-Stage Development. Cell Host Microbe 2018; 23:557-569.e9. [PMID: 29649445 PMCID: PMC5899830 DOI: 10.1016/j.chom.2018.03.007] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/05/2018] [Accepted: 03/05/2018] [Indexed: 02/07/2023]
Abstract
Underlying the development of malaria parasites within erythrocytes and the resulting pathogenicity is a hardwired program that secures proper timing of gene transcription and production of functionally relevant proteins. How stage-specific gene expression is orchestrated in vivo remains unclear. Here, using the assay for transposase accessible chromatin sequencing (ATAC-seq), we identified ∼4,000 regulatory regions in P. falciparum intraerythrocytic stages. The vast majority of these sites are located within 2 kb upstream of transcribed genes and their chromatin accessibility pattern correlates positively with abundance of the respective mRNA transcript. Importantly, these regions are sufficient to drive stage-specific reporter gene expression and DNA motifs enriched in stage-specific sets of regulatory regions interact with members of the P. falciparum AP2 transcription factor family. Collectively, this study provides initial insights into the in vivo gene regulatory network of P. falciparum intraerythrocytic stages and should serve as a valuable resource for future studies.
Collapse
Affiliation(s)
- Christa Geeke Toenhake
- Radboud University, Faculty of Science, Department of Molecular Biology, Nijmegen, 6525 GA, the Netherlands
| | | | | | - David Robert Westhead
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Simon Jan van Heeringen
- Radboud University, Faculty of Science, Department of Molecular Developmental Biology, Nijmegen, 6525 GA, the Netherlands
| | - Richárd Bártfai
- Radboud University, Faculty of Science, Department of Molecular Biology, Nijmegen, 6525 GA, the Netherlands.
| |
Collapse
|
28
|
Kanyal A, Rawat M, Gurung P, Choubey D, Anamika K, Karmodiya K. Genome‐wide survey and phylogenetic analysis of histone acetyltransferases and histone deacetylases of
Plasmodium falciparum. FEBS J 2018; 285:1767-1782. [DOI: 10.1111/febs.14376] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/20/2017] [Accepted: 12/22/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Abhishek Kanyal
- Department of Biology Indian Institute of Science Education and Research Pashan, Pune India
| | - Mukul Rawat
- Department of Biology Indian Institute of Science Education and Research Pashan, Pune India
| | - Pratima Gurung
- Department of Biology Indian Institute of Science Education and Research Pashan, Pune India
| | | | | | - Krishanpal Karmodiya
- Department of Biology Indian Institute of Science Education and Research Pashan, Pune India
| |
Collapse
|
29
|
Lu X, Batugedara G, Lee M, Prudhomme J, Bunnik EM, Le Roch K. Nascent RNA sequencing reveals mechanisms of gene regulation in the human malaria parasite Plasmodium falciparum. Nucleic Acids Res 2017; 45:7825-7840. [PMID: 28531310 PMCID: PMC5737683 DOI: 10.1093/nar/gkx464] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 12/18/2022] Open
Abstract
Gene expression in Plasmodium falciparum is tightly regulated to ensure successful propagation of the parasite throughout its complex life cycle. The earliest transcriptomics studies in P. falciparum suggested a cascade of transcriptional activity over the course of the 48-hour intraerythrocytic developmental cycle (IDC); however, the just-in-time transcriptional model has recently been challenged by findings that show the importance of post-transcriptional regulation. To further explore the role of transcriptional regulation, we performed the first genome-wide nascent RNA profiling in P. falciparum. Our findings indicate that the majority of genes are transcribed simultaneously during the trophozoite stage of the IDC and that only a small subset of genes is subject to differential transcriptional timing. RNA polymerase II is engaged with promoter regions prior to this transcriptional burst, suggesting that Pol II pausing plays a dominant role in gene regulation. In addition, we found that the overall transcriptional program during gametocyte differentiation is surprisingly similar to the IDC, with the exception of relatively small subsets of genes. Results from this study suggest that further characterization of the molecular players that regulate stage-specific gene expression and Pol II pausing will contribute to our continuous search for novel antimalarial drug targets.
Collapse
MESH Headings
- Animals
- Epigenesis, Genetic
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Genes, Protozoan
- Humans
- Malaria, Falciparum/blood
- Malaria, Falciparum/parasitology
- Plasmodium falciparum/genetics
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/pathogenicity
- Promoter Regions, Genetic
- RNA Polymerase II/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- Sequence Analysis, RNA
- Transcription, Genetic
Collapse
Affiliation(s)
- Xueqing Maggie Lu
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
| | - Gayani Batugedara
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
| | - Michael Lee
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
| | - Jacques Prudhomme
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
| | - Evelien M. Bunnik
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
- Department of Microbiology, Immunology and Molecular Genetics, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Karine G. Le Roch
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA
| |
Collapse
|
30
|
Abstract
Organisms with identical genome sequences can show substantial differences in their phenotypes owing to epigenetic changes that result in different use of their genes. Epigenetic regulation of gene expression plays a key role in the control of several fundamental processes in the biology of malaria parasites, including antigenic variation and sexual differentiation. Some of the histone modifications and chromatin-modifying enzymes that control the epigenetic states of malaria genes have been characterized, and their functions are beginning to be unraveled. The fundamental principles of epigenetic regulation of gene expression appear to be conserved between malaria parasites and model eukaryotes, but important peculiarities exist. Here, we review the current knowledge of malaria epigenetics and discuss how it can be exploited for the development of new molecular markers and new types of drugs that may contribute to malaria eradication efforts.
Collapse
Affiliation(s)
- Alfred Cortés
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia 08036, Spain.,ICREA, Barcelona, Catalonia 08010, Spain
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065
| |
Collapse
|
31
|
Santos JM, Josling G, Ross P, Joshi P, Orchard L, Campbell T, Schieler A, Cristea IM, Llinás M. Red Blood Cell Invasion by the Malaria Parasite Is Coordinated by the PfAP2-I Transcription Factor. Cell Host Microbe 2017; 21:731-741.e10. [PMID: 28618269 PMCID: PMC5855115 DOI: 10.1016/j.chom.2017.05.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 02/16/2017] [Accepted: 05/23/2017] [Indexed: 10/19/2022]
Abstract
Obligate intracellular parasites must efficiently invade host cells in order to mature and be transmitted. For the malaria parasite Plasmodium falciparum, invasion of host red blood cells (RBCs) is essential. Here we describe a parasite-specific transcription factor PfAP2-I, belonging to the Apicomplexan AP2 (ApiAP2) family, that is responsible for regulating the expression of genes involved in RBC invasion. Our genome-wide analysis by ChIP-seq shows that PfAP2-I interacts with a specific DNA motif in the promoters of target genes. Although PfAP2-I contains three AP2 DNA-binding domains, only one is required for binding of the target genes during blood stage development. Furthermore, we find that PfAP2-I associates with several chromatin-associated proteins, including the Plasmodium bromodomain protein PfBDP1 and that complex formation is associated with transcriptional regulation. As a key regulator of red blood cell invasion, PfAP2-I represents a potential new antimalarial therapeutic target.
Collapse
Affiliation(s)
- Joana Mendonca Santos
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Gabrielle Josling
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Philipp Ross
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Preeti Joshi
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lindsey Orchard
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Tracey Campbell
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Ariel Schieler
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry and Huck Center for Infectious Disease Dynamics, Pennsylvania State University, State College, PA 16802, USA.
| |
Collapse
|
32
|
Gupta AP, Bozdech Z. Epigenetic landscapes underlining global patterns of gene expression in the human malaria parasite, Plasmodium falciparum. Int J Parasitol 2017; 47:399-407. [PMID: 28414071 DOI: 10.1016/j.ijpara.2016.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/15/2016] [Accepted: 10/20/2016] [Indexed: 12/31/2022]
Abstract
The dynamic chromatin landscape displaying combinatorial complexity of the epigenome impacts gene expression that underlies many events of differentiation and cell cycle progression. In the past few years, epigenetic mechanisms have emerged as important processes involved in the tight gene regulation in malaria parasites, Plasmodium spp. Focusing predominantly on Plasmodium falciparum, the species associated with the most severe form of the disease, many advances have been made in our understanding of the interaction between transcriptional regulation and epigenetic mechanisms as the pivotal processes in regulating life cycle progression, host parasite interactions and parasite adaptation to the host environment. This review focuses on the epigenome and its effect on transcriptional regulation in P. falciparum, highlighting its unique, evolutionary diverse features.
Collapse
Affiliation(s)
- Archana P Gupta
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| |
Collapse
|
33
|
Bernardes J, Zaverucha G, Vaquero C, Carbone A. Improvement in Protein Domain Identification Is Reached by Breaking Consensus, with the Agreement of Many Profiles and Domain Co-occurrence. PLoS Comput Biol 2016; 12:e1005038. [PMID: 27472895 PMCID: PMC4966962 DOI: 10.1371/journal.pcbi.1005038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 06/28/2016] [Indexed: 11/30/2022] Open
Abstract
Traditional protein annotation methods describe known domains with probabilistic models representing consensus among homologous domain sequences. However, when relevant signals become too weak to be identified by a global consensus, attempts for annotation fail. Here we address the fundamental question of domain identification for highly divergent proteins. By using high performance computing, we demonstrate that the limits of state-of-the-art annotation methods can be bypassed. We design a new strategy based on the observation that many structural and functional protein constraints are not globally conserved through all species but might be locally conserved in separate clades. We propose a novel exploitation of the large amount of data available: 1. for each known protein domain, several probabilistic clade-centered models are constructed from a large and differentiated panel of homologous sequences, 2. a decision-making protocol combines outcomes obtained from multiple models, 3. a multi-criteria optimization algorithm finds the most likely protein architecture. The method is evaluated for domain and architecture prediction over several datasets and statistical testing hypotheses. Its performance is compared against HMMScan and HHblits, two widely used search methods based on sequence-profile and profile-profile comparison. Due to their closeness to actual protein sequences, clade-centered models are shown to be more specific and functionally predictive than the broadly used consensus models. Based on them, we improved annotation of Plasmodium falciparum protein sequences on a scale not previously possible. We successfully predict at least one domain for 72% of P. falciparum proteins against 63% achieved previously, corresponding to 30% of improvement over the total number of Pfam domain predictions on the whole genome. The method is applicable to any genome and opens new avenues to tackle evolutionary questions such as the reconstruction of ancient domain duplications, the reconstruction of the history of protein architectures, and the estimation of protein domain age. Website and software: http://www.lcqb.upmc.fr/CLADE. Current sequence databases contain hundreds of billions of nucleotides coding for genes and a classification of these sequences is a primary problem in genomics. A reasonable way to organize these sequences is through their predicted domains, but the identification of domains in very divergent sequences, spanning the entire phylogenetic tree of species, is a difficult problem. By generating multiple probabilistic models for a domain, describing the spread of evolutionary patterns in different phylogenetic clades, we can effectively explore domains that are likely to be coded in gene sequences. Through a machine learning approach and optimization techniques, coding for expected evolutionary constraints, we filter the many possibilities of domain identification found for a gene and propose the most likely domain architecture associated to it. The application of this novel approach to the full genome of Plasmodium falciparum, to a dataset of sequences from three SCOP datasets highlights the interest of exploring multiple pathways of domain evolution in the aim of extracting biological information from genomic sequences. Our new computational approach was developed with the hope of providing a novel tier of accurate and precise tools that complement existing tools such as HMMer, HHblits and PSI-BLAST, by exploring in a novel way the large amount of sequence data available. The existence of powerful databases for sequences, domains and architectures help make this hope a reality.
Collapse
Affiliation(s)
- Juliana Bernardes
- Sorbonne Universités, UPMC Univ-Paris 6, CNRS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
- * E-mail: (JB); (AC)
| | - Gerson Zaverucha
- COPPE, Programa de Engenharia de Sistemas e Computação, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Catherine Vaquero
- Sorbonne Universités, UPMC Univ-Paris 6, INSERM U1135, CNRS ERL 8255, Centre d’Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Alessandra Carbone
- Sorbonne Universités, UPMC Univ-Paris 6, CNRS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
- Institut Universitaire de France, Paris, France
- * E-mail: (JB); (AC)
| |
Collapse
|
34
|
Bunnik EM, Batugedara G, Saraf A, Prudhomme J, Florens L, Le Roch KG. The mRNA-bound proteome of the human malaria parasite Plasmodium falciparum. Genome Biol 2016; 17:147. [PMID: 27381095 PMCID: PMC4933991 DOI: 10.1186/s13059-016-1014-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 06/20/2016] [Indexed: 02/08/2023] Open
Abstract
Background Gene expression is controlled at multiple levels, including transcription, stability, translation, and degradation. Over the years, it has become apparent that Plasmodium falciparum exerts limited transcriptional control of gene expression, while at least part of Plasmodium’s genome is controlled by post-transcriptional mechanisms. To generate insights into the mechanisms that regulate gene expression at the post-transcriptional level, we undertook complementary computational, comparative genomics, and experimental approaches to identify and characterize mRNA-binding proteins (mRBPs) in P. falciparum. Results Close to 1000 RNA-binding proteins are identified by hidden Markov model searches, of which mRBPs encompass a relatively large proportion of the parasite proteome as compared to other eukaryotes. Several abundant mRNA-binding domains are enriched in apicomplexan parasites, while strong depletion of mRNA-binding domains involved in RNA degradation is observed. Next, we experimentally capture 199 proteins that interact with mRNA during the blood stages, 64 of which with high confidence. These captured mRBPs show a significant overlap with the in silico identified candidate RBPs (p < 0.0001). Among the experimentally validated mRBPs are many known translational regulators active in other stages of the parasite’s life cycle, such as DOZI, CITH, PfCELF2, Musashi, and PfAlba1–4. Finally, we also detect several proteins with an RNA-binding domain abundant in Apicomplexans (RAP domain) that is almost exclusively found in apicomplexan parasites. Conclusions Collectively, our results provide the most complete comparative genomics and experimental analysis of mRBPs in P. falciparum. A better understanding of these regulatory proteins will not only give insight into the intricate parasite life cycle but may also provide targets for novel therapeutic strategies. Electronic supplementary material The online version of this article (doi:10.1186/s13059-016-1014-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Evelien M Bunnik
- Department of Cell Biology and Neuroscience, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Gayani Batugedara
- Department of Cell Biology and Neuroscience, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Anita Saraf
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO, 64110, USA
| | - Jacques Prudhomme
- Department of Cell Biology and Neuroscience, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO, 64110, USA
| | - Karine G Le Roch
- Department of Cell Biology and Neuroscience, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA.
| |
Collapse
|
35
|
Tilley L, Straimer J, Gnädig NF, Ralph SA, Fidock DA. Artemisinin Action and Resistance in Plasmodium falciparum. Trends Parasitol 2016; 32:682-696. [PMID: 27289273 DOI: 10.1016/j.pt.2016.05.010] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/10/2016] [Accepted: 05/13/2016] [Indexed: 12/16/2022]
Abstract
The worldwide use of artemisinin-based combination therapies (ACTs) has contributed in recent years to a substantial reduction in deaths resulting from Plasmodium falciparum malaria. Resistance to artemisinins, however, has emerged in Southeast Asia. Clinically, resistance is defined as a slower rate of parasite clearance in patients treated with an artemisinin derivative or an ACT. These slow clearance rates associate with enhanced survival rates of ring-stage parasites briefly exposed in vitro to dihydroartemisinin. We describe recent progress made in defining the molecular basis of artemisinin resistance, which has identified a primary role for the P. falciparum K13 protein. Using K13 mutations as molecular markers, epidemiological studies are now tracking the emergence and spread of artemisinin resistance. Mechanistic studies suggest potential ways to overcome resistance.
Collapse
Affiliation(s)
- Leann Tilley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia.
| | - Judith Straimer
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Nina F Gnädig
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Stuart A Ralph
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA; Division of Infectious Diseases, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
| |
Collapse
|
36
|
Adjalley SH, Chabbert CD, Klaus B, Pelechano V, Steinmetz LM. Landscape and Dynamics of Transcription Initiation in the Malaria Parasite Plasmodium falciparum. Cell Rep 2016; 14:2463-75. [PMID: 26947071 DOI: 10.1016/j.celrep.2016.02.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 12/09/2015] [Accepted: 02/01/2016] [Indexed: 12/20/2022] Open
Abstract
A comprehensive map of transcription start sites (TSSs) across the highly AT-rich genome of P. falciparum would aid progress toward deciphering the molecular mechanisms that underlie the timely regulation of gene expression in this malaria parasite. Using high-throughput sequencing technologies, we generated a comprehensive atlas of transcription initiation events at single-nucleotide resolution during the parasite intra-erythrocytic developmental cycle. This detailed analysis of TSS usage enabled us to define architectural features of plasmodial promoters. We demonstrate that TSS selection and strength are constrained by local nucleotide composition. Furthermore, we provide evidence for coordinate and stage-specific TSS usage from distinct sites within the same transcription unit, thereby producing transcript isoforms, a subset of which are developmentally regulated. This work offers a framework for further investigations into the interactions between genomic sequences and regulatory factors governing the complex transcriptional program of this major human pathogen.
Collapse
Affiliation(s)
- Sophie H Adjalley
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Christophe D Chabbert
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Bernd Klaus
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Vicent Pelechano
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Lars M Steinmetz
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Stanford Genome Technology Center, Palo Alto, CA 94304, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
37
|
Reddy BPN, Shrestha S, Hart KJ, Liang X, Kemirembe K, Cui L, Lindner SE. A bioinformatic survey of RNA-binding proteins in Plasmodium. BMC Genomics 2015; 16:890. [PMID: 26525978 PMCID: PMC4630921 DOI: 10.1186/s12864-015-2092-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 10/15/2015] [Indexed: 11/10/2022] Open
Abstract
Background The malaria parasites in the genus Plasmodium have a very complicated life cycle involving an invertebrate vector and a vertebrate host. RNA-binding proteins (RBPs) are critical factors involved in every aspect of the development of these parasites. However, very few RBPs have been functionally characterized to date in the human parasite Plasmodium falciparum. Methods Using different bioinformatic methods and tools we searched P. falciparum genome to list and annotate RBPs. A representative 3D models for each of the RBD domain identified in P. falciparum was created using I-TESSAR and SWISS-MODEL. Microarray and RNAseq data analysis pertaining PfRBPs was performed using MeV software. Finally, Cytoscape was used to create protein-protein interaction network for CITH-Dozi and Caf1-CCR4-Not complexes. Results We report the identification of 189 putative RBP genes belonging to 13 different families in Plasmodium, which comprise 3.5 % of all annotated genes. Almost 90 % (169/189) of these genes belong to six prominent RBP classes, namely RNA recognition motifs, DEAD/H-box RNA helicases, K homology, Zinc finger, Puf and Alba gene families. Interestingly, almost all of the identified RNA-binding helicases and KH genes have cognate homologs in model species, suggesting their evolutionary conservation. Exploration of the existing P. falciparum blood-stage transcriptomes revealed that most RBPs have peak mRNA expression levels early during the intraerythrocytic development cycle, which taper off in later stages. Nearly 27 % of RBPs have elevated expression in gametocytes, while 47 and 24 % have elevated mRNA expression in ookinete and asexual stages. Comparative interactome analyses using human and Plasmodium protein-protein interaction datasets suggest extensive conservation of the PfCITH/PfDOZI and PfCaf1-CCR4-NOT complexes. Conclusions The Plasmodium parasites possess a large number of putative RBPs belonging to most of RBP families identified so far, suggesting the presence of extensive post-transcriptional regulation in these parasites. Taken together, in silico identification of these putative RBPs provides a foundation for future functional studies aimed at defining a unique network of post-transcriptional regulation in P. falciparum. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2092-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- B P Niranjan Reddy
- Department of Entomology, Center for Malaria Research, Pennsylvania State University, 501 ASI Bldg, University Park, PA, 16802, USA
| | - Sony Shrestha
- Department of Entomology, Center for Malaria Research, Pennsylvania State University, 501 ASI Bldg, University Park, PA, 16802, USA
| | - Kevin J Hart
- Department of Biochemistry and Molecular Biology, Center for Malaria Research, Pennsylvania State University, W223 Millennium Science Complex, University Park, PA, 16802, USA
| | - Xiaoying Liang
- Department of Entomology, Center for Malaria Research, Pennsylvania State University, 501 ASI Bldg, University Park, PA, 16802, USA
| | - Karen Kemirembe
- Department of Entomology, Center for Malaria Research, Pennsylvania State University, 501 ASI Bldg, University Park, PA, 16802, USA
| | - Liwang Cui
- Department of Entomology, Center for Malaria Research, Pennsylvania State University, 501 ASI Bldg, University Park, PA, 16802, USA.
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Center for Malaria Research, Pennsylvania State University, W223 Millennium Science Complex, University Park, PA, 16802, USA.
| |
Collapse
|
38
|
Abstract
Malaria is caused by a unicellular protozoan pathogen of the genus Plasmodium. Although genes represent monocistronic units that are expressed in a life cycle stage-specific manner, post-transcriptional regulation via translational repression of mRNA has been observed in parasite stages that transition from the vertebrate host to the Anopheles vector. An interesting new type of post-transcriptional control was recently discovered in Plasmodium falciparum stages that infect human erythrocytes. A subgroup of genes that were thought to be transcriptionally silent are actually transcribed but degraded immediately by an RNase II that is recruited to these gene loci. This cryptic RNA is not detectable in steady-state RNA but has been detected using nuclear run-on techniques and in mutant RNase II parasites. Nascent RNA degradation controls virulence genes expressed in a monoallelic fashion and noncoding RNAs (ncRNAs), but also a number of housekeeping-like of genes. More studies on other life cycle stages may reveal the full extent of this type of gene regulation in malaria parasites. It is tempting to speculate that RNase II-mediated gene control may exist in other eukaryotic organisms.
Collapse
Affiliation(s)
- Qingfeng Zhang
- a Research Center for Translational Medicine; Key Laboratory of Arrhythmias of the Ministry of Education; Shanghai East Hospital; Tongji University School of Medicine ; Shanghai , China
| | | |
Collapse
|
39
|
Isewon I, Oyelade J, Brors B, Adebiyi E. In Silico Gene Regulatory Network of the Maurer's Cleft Pathway in Plasmodium falciparum. Evol Bioinform Online 2015; 11:231-8. [PMID: 26526876 PMCID: PMC4620995 DOI: 10.4137/ebo.s25585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 07/28/2015] [Accepted: 08/03/2015] [Indexed: 11/15/2022] Open
Abstract
The Maurer's clefts (MCs) are very important for the survival of Plasmodium falciparum within an infected cell as they are induced by the parasite itself in the erythrocyte for protein trafficking. The MCs form an interesting part of the parasite's biology as they shed more light on how the parasite remodels the erythrocyte leading to host pathogenesis and death. Here, we predicted and analyzed the genetic regulatory network of genes identified to belong to the MCs using regularized graphical Gaussian model. Our network shows four major activators, their corresponding target genes, and predicted binding sites. One of these master activators is the serine repeat antigen 5 (SERA5), predominantly expressed among the SERA multigene family of P. falciparum, which is one of the blood-stage malaria vaccine candidates. Our results provide more details about functional interactions and the regulation of the genes in the MCs’ pathway of P. falciparum.
Collapse
Affiliation(s)
- Itunuoluwa Isewon
- Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Jelili Oyelade
- Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Benedikt Brors
- Department of Applied Bioinformatics, German Cancer Research Centre (DKFZ), Heidelberg, Germany
| | - Ezekiel Adebiyi
- Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
- Department of Applied Bioinformatics, German Cancer Research Centre (DKFZ), Heidelberg, Germany
| |
Collapse
|
40
|
Genome-Wide Collation of the Plasmodium falciparum WDR Protein Superfamily Reveals Malarial Parasite-Specific Features. PLoS One 2015; 10:e0128507. [PMID: 26043001 PMCID: PMC4456382 DOI: 10.1371/journal.pone.0128507] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 04/29/2015] [Indexed: 01/10/2023] Open
Abstract
Despite a significant drop in malaria deaths during the past decade, malaria continues to be one of the biggest health problems around the globe. WD40 repeats (WDRs) containing proteins comprise one of the largest and functionally diverse protein superfamily in eukaryotes, acting as scaffolds for assembling large protein complexes. In the present study, we report an extensive in silico analysis of the WDR gene family in human malaria parasite Plasmodium falciparum. Our genome-wide identification has revealed 80 putative WDR genes in P. falciparum (PfWDRs). Five distinct domain compositions were discovered in Plasmodium as compared to the human host. Notably, 31 PfWDRs were annotated/re-annotated on the basis of their orthologs in other species. Interestingly, most PfWDRs were larger as compared to their human homologs highlighting the presence of parasite-specific insertions. Fifteen PfWDRs appeared specific to the Plasmodium with no assigned orthologs. Expression profiling of PfWDRs revealed a mixture of linear and nonlinear relationships between transcriptome and proteome, and only nine PfWDRs were found to be stage-specific. Homology modeling identified conservation of major binding sites in PfCAF-1 and PfRACK. Protein-protein interaction network analyses suggested that PfWDRs are highly connected proteins with ~1928 potential interactions, supporting their role as hubs in cellular networks. The present study highlights the roles and relevance of the WDR family in P. falciparum, and identifies unique features that lay a foundation for further experimental dissection of PfWDRs.
Collapse
|
41
|
Josling G, Petter M, Oehring S, Gupta A, Dietz O, Wilson D, Schubert T, Längst G, Gilson P, Crabb B, Moes S, Jenoe P, Lim S, Brown G, Bozdech Z, Voss T, Duffy M. A Plasmodium Falciparum Bromodomain Protein Regulates Invasion Gene Expression. Cell Host Microbe 2015; 17:741-51. [DOI: 10.1016/j.chom.2015.05.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/30/2015] [Accepted: 05/14/2015] [Indexed: 11/27/2022]
|
42
|
Disruption of Parasite hmgb2 Gene Attenuates Plasmodium berghei ANKA Pathogenicity. Infect Immun 2015; 83:2771-84. [PMID: 25916985 DOI: 10.1128/iai.03129-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/19/2015] [Indexed: 12/20/2022] Open
Abstract
Eukaryotic high-mobility-group-box (HMGB) proteins are nuclear factors involved in chromatin remodeling and transcription regulation. When released into the extracellular milieu, HMGB1 acts as a proinflammatory cytokine that plays a central role in the pathogenesis of several immune-mediated inflammatory diseases. We found that the Plasmodium genome encodes two genuine HMGB factors, Plasmodium HMGB1 and HMGB2, that encompass, like their human counterparts, a proinflammatory domain. Given that these proteins are released from parasitized red blood cells, we then hypothesized that Plasmodium HMGB might contribute to the pathogenesis of experimental cerebral malaria (ECM), a lethal neuroinflammatory syndrome that develops in C57BL/6 (susceptible) mice infected with Plasmodium berghei ANKA and that in many aspects resembles human cerebral malaria elicited by P. falciparum infection. The pathogenesis of experimental cerebral malaria was suppressed in C57BL/6 mice infected with P. berghei ANKA lacking the hmgb2 gene (Δhmgb2 ANKA), an effect associated with a reduction of histological brain lesions and with lower expression levels of several proinflammatory genes. The incidence of ECM in pbhmgb2-deficient mice was restored by the administration of recombinant PbHMGB2. Protection from experimental cerebral malaria in Δhmgb2 ANKA-infected mice was associated with reduced sequestration in the brain of CD4(+) and CD8(+) T cells, including CD8(+) granzyme B(+) and CD8(+) IFN-γ(+) cells, and, to some extent, neutrophils. This was consistent with a reduced parasite sequestration in the brain, lungs, and spleen, though to a lesser extent than in wild-type P. berghei ANKA-infected mice. In summary, Plasmodium HMGB2 acts as an alarmin that contributes to the pathogenesis of cerebral malaria.
Collapse
|
43
|
Abstract
Post-translational modifications play crucial parts in regulating protein function and thereby control several fundamental aspects of eukaryotic biology, including cell signalling, protein trafficking, epigenetic control of gene expression, cell-cell interactions, and cell proliferation and differentiation. In this Review, we discuss protein modifications that have been shown to have a key role in malaria parasite biology and pathogenesis. We focus on phosphorylation, acetylation, methylation and lipidation. We provide an overview of the biological significance of these modifications and discuss prospects and progress in antimalarial drug discovery based on the inhibition of the enzymes that mediate these modifications.
Collapse
|
44
|
Ukaegbu UE, Kishore SP, Kwiatkowski DL, Pandarinath C, Dahan-Pasternak N, Dzikowski R, Deitsch KW. Recruitment of PfSET2 by RNA polymerase II to variant antigen encoding loci contributes to antigenic variation in P. falciparum. PLoS Pathog 2014; 10:e1003854. [PMID: 24391504 PMCID: PMC3879369 DOI: 10.1371/journal.ppat.1003854] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 11/12/2013] [Indexed: 11/18/2022] Open
Abstract
Histone modifications are important regulators of gene expression in all eukaryotes. In Plasmodium falciparum, these epigenetic marks regulate expression of genes involved in several aspects of host-parasite interactions, including antigenic variation. While the identities and genomic positions of many histone modifications have now been cataloged, how they are targeted to defined genomic regions remains poorly understood. For example, how variant antigen encoding loci (var) are targeted for deposition of unique histone marks is a mystery that continues to perplex the field. Here we describe the recruitment of an ortholog of the histone modifier SET2 to var genes through direct interactions with the C-terminal domain (CTD) of RNA polymerase II. In higher eukaryotes, SET2 is a histone methyltransferase recruited by RNA pol II during mRNA transcription; however, the ortholog in P. falciparum (PfSET2) has an atypical architecture and its role in regulating transcription is unknown. Here we show that PfSET2 binds to the unphosphorylated form of the CTD, a property inconsistent with its recruitment during mRNA synthesis. Further, we show that H3K36me3, the epigenetic mark deposited by PfSET2, is enriched at both active and silent var gene loci, providing additional evidence that its recruitment is not associated with mRNA production. Over-expression of a dominant negative form of PfSET2 designed to disrupt binding to RNA pol II induced rapid var gene expression switching, confirming both the importance of PfSET2 in var gene regulation and a role for RNA pol II in its recruitment. RNA pol II is known to transcribe non-coding RNAs from both active and silent var genes, providing a possible mechanism by which it could recruit PfSET2 to var loci. This work unifies previous reports of histone modifications, the production of ncRNAs, and the promoter activity of var introns into a mechanism that contributes to antigenic variation by malaria parasites. Chemical modifications to histones, the proteins that serve as the primary units of chromatin, often determine whether specific genes are actively transcribed or condensed into transcriptionally silent regions of the genome. In the malaria parasite Plasmodium falciparum, histone modifications have been shown to play a significant role in controlling gene expression involved in many aspects of their lifecycle, including the complex gene expression patterns associated with antigenic variation. The various histone modifications that are found within the parasite's genome have now been extensively cataloged, and the enzymes that are responsible for adding and removing them have been identified. However, how these enzymes are recruited to specific regions of the genome to coordinate gene expression is not understood. In this paper, we provide the first evidence for recruitment of a unique histone methyltransferase to specific regions of the genome through its tethering to RNA polymerase II. We find that disruption of this interaction results in major changes in expression patterns of genes involved in antigenic variation, demonstrating the importance of regulated recruitment of histone modifiers for parasite biology.
Collapse
Affiliation(s)
- Uchechi E Ukaegbu
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Sandeep P Kishore
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Dacia L Kwiatkowski
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Chethan Pandarinath
- Program in Computational Biology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Noa Dahan-Pasternak
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ron Dzikowski
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| |
Collapse
|
45
|
Duffy MF, Selvarajah SA, Josling GA, Petter M. Epigenetic regulation of the Plasmodium falciparum genome. Brief Funct Genomics 2013; 13:203-16. [PMID: 24326119 DOI: 10.1093/bfgp/elt047] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent research has highlighted some unique aspects of chromatin biology in the malaria parasite Plasmodium falciparum. During its erythrocytic lifecycle P. falciparum maintains its genome primarily as unstructured euchromatin. Indeed there is no clear role for chromatin-mediated silencing of the majority of the developmentally expressed genes in P. falciparum. However discontinuous stretches of heterochromatin are critical for variegated expression of contingency genes that mediate key pathogenic processes in malaria. These range from invasion of erythrocytes and antigenic variation to solute transport and growth adaptation in response to environmental changes. Despite lack of structure within euchromatin the nucleus maintains functional compartments that regulate expression of many genes at the nuclear periphery, particularly genes with clonally variant expression. The typical components of the chromatin regulatory machinery are present in P. falciparum; however, some of these appear to have evolved novel species-specific functions, e.g. the dynamic regulation of histone variants at virulence gene promoters. The parasite also appears to have repeatedly acquired chromatin regulatory proteins through lateral transfer from endosymbionts and from the host. P. falciparum chromatin regulators have been successfully targeted with multiple drugs in laboratory studies; hopefully their functional divergence from human counterparts will allow the development of parasite-specific inhibitors.
Collapse
|
46
|
Gupta AP, Chin WH, Zhu L, Mok S, Luah YH, Lim EH, Bozdech Z. Dynamic epigenetic regulation of gene expression during the life cycle of malaria parasite Plasmodium falciparum. PLoS Pathog 2013; 9:e1003170. [PMID: 23468622 PMCID: PMC3585154 DOI: 10.1371/journal.ppat.1003170] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 12/17/2012] [Indexed: 12/19/2022] Open
Abstract
Epigenetic mechanisms are emerging as one of the major factors of the dynamics of gene expression in the human malaria parasite, Plasmodium falciparum. To elucidate the role of chromatin remodeling in transcriptional regulation associated with the progression of the P. falciparum intraerythrocytic development cycle (IDC), we mapped the temporal pattern of chromosomal association with histone H3 and H4 modifications using ChIP-on-chip. Here, we have generated a broad integrative epigenomic map of twelve histone modifications during the P. falciparum IDC including H4K5ac, H4K8ac, H4K12ac, H4K16ac, H3K9ac, H3K14ac, H3K56ac, H4K20me1, H4K20me3, H3K4me3, H3K79me3 and H4R3me2. While some modifications were found to be associated with the vast majority of the genome and their occupancy was constant, others showed more specific and highly dynamic distribution. Importantly, eight modifications displaying tight correlations with transcript levels showed differential affinity to distinct genomic regions with H4K8ac occupying predominantly promoter regions while others occurred at the 5′ ends of coding sequences. The promoter occupancy of H4K8ac remained unchanged when ectopically inserted at a different locus, indicating the presence of specific DNA elements that recruit histone modifying enzymes regardless of their broad chromatin environment. In addition, we showed the presence of multivalent domains on the genome carrying more than one histone mark, highlighting the importance of combinatorial effects on transcription. Overall, our work portrays a substantial association between chromosomal locations of various epigenetic markers, transcriptional activity and global stage-specific transitions in the epigenome. Malaria is a devastating parasitic disease caused by the protozoan protist Plasmodium falciparum. The complex life cycle of P. falciparum comprises various morphological and functionally distinct forms and is completed in two different hosts. Various regulatory mechanisms are employed by these parasites to complete their life cycle and survive in human hosts. Epigenetic mechanisms, though not fully explored, have been implicated as one of the key players in gene regulation, morphological differentiation and antigenic variation. Here, we present a comprehensive epigenetic map of 12 histone post-translational modifications during the intraerythrocytic life cycle of P. falciparum. We have been able to identify at least eight histone modifications whose dynamic patterns correlate with the transcriptional regulation across the life cycle. In particular, we have shown that a set of euchromatic histone marks work in synergy, creating a dynamic unique histone code that is linked with gene expression during the progression of the Plasmodium intraerythrocytic developmental cycle. These findings enhance our knowledge of complex gene regulation and will help to identify novel targets for fighting malaria.
Collapse
Affiliation(s)
- Archna P. Gupta
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Wai Hoe Chin
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Lei Zhu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sachel Mok
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yen-Hoon Luah
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Eng-How Lim
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
| |
Collapse
|
47
|
Hoeijmakers WAM, Salcedo-Amaya AM, Smits AH, Françoijs KJ, Treeck M, Gilberger TW, Stunnenberg HG, Bártfai R. H2A.Z/H2B.Z double-variant nucleosomes inhabit the AT-rich promoter regions of the Plasmodium falciparum genome. Mol Microbiol 2013; 87:1061-73. [PMID: 23320541 PMCID: PMC3594968 DOI: 10.1111/mmi.12151] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2013] [Indexed: 02/06/2023]
Abstract
Histone variants are key components of the epigenetic code and evolved to perform specific functions in transcriptional regulation, DNA repair, chromosome segregation and other fundamental processes. Although variants for histone H2A and H3 are found throughout the eukaryotic kingdom, variants of histone H2B and H4 are rarely encountered. H2B.Z is one of those rare H2B variants and is apicomplexan-specific. Here we show that in Plasmodium falciparum H2B.Z localizes to euchromatic intergenic regions throughout intraerythrocytic development and together with H2A.Z forms a double-variant nucleosome subtype. These nucleosomes are enriched in promoters over 3′ intergenic regions and their occupancy generally correlates with the strength of the promoter, but not with its temporal activity. Remarkably, H2B.Z occupancy levels exhibit a clear correlation with the base-composition of the underlying DNA, raising the intriguing possibility that the extreme AT content of the intergenic regions within the Plasmodium genome might be instructive for histone variant deposition. In summary, our data show that the H2A.Z/H2B.Z double-variant nucleosome demarcates putative regulatory regions of the P. falciparum epigenome and likely provides a scaffold for dynamic regulation of gene expression in this deadly human pathogen.
Collapse
Affiliation(s)
- Wieteke A M Hoeijmakers
- Department of Molecular Biology, Radboud University, Nijmegen Centre for Molecular Life Sciences, Nijmegen 6525GA, the Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Cai H, Hong C, Gu J, Lilburn TG, Kuang R, Wang Y. Module-based subnetwork alignments reveal novel transcriptional regulators in malaria parasite Plasmodium falciparum. BMC SYSTEMS BIOLOGY 2012; 6 Suppl 3:S5. [PMID: 23282319 PMCID: PMC3524314 DOI: 10.1186/1752-0509-6-s3-s5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background Malaria causes over one million deaths annually, posing an enormous health and economic burden in endemic regions. The completion of genome sequencing of the causative agents, a group of parasites in the genus Plasmodium, revealed potential drug and vaccine candidates. However, genomics-driven target discovery has been significantly hampered by our limited knowledge of the cellular networks associated with parasite development and pathogenesis. In this paper, we propose an approach based on aligning neighborhood PPI subnetworks across species to identify network components in the malaria parasite P. falciparum. Results Instead of only relying on sequence similarities to detect functional orthologs, our approach measures the conservation between the neighborhood subnetworks in protein-protein interaction (PPI) networks in two species, P. falciparum and E. coli. 1,082 P. falciparum proteins were predicted as functional orthologs of known transcriptional regulators in the E. coli network, including general transcriptional regulators, parasite-specific transcriptional regulators in the ApiAP2 protein family, and other potential regulatory proteins. They are implicated in a variety of cellular processes involving chromatin remodeling, genome integrity, secretion, invasion, protein processing, and metabolism. Conclusions In this proof-of-concept study, we demonstrate that a subnetwork alignment approach can reveal previously uncharacterized members of the subnetworks, which opens new opportunities to identify potential therapeutic targets and provide new insights into parasite biology, pathogenesis and virulence. This approach can be extended to other systems, especially those with poor genome annotation and a paucity of knowledge about cellular networks.
Collapse
Affiliation(s)
- Hong Cai
- Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | | | | | | | | | | |
Collapse
|
49
|
Pino P, Sebastian S, Kim E, Bush E, Brochet M, Volkmann K, Kozlowski E, Llinás M, Billker O, Soldati-Favre D. A Tetracycline-Repressible Transactivator System to Study Essential Genes in Malaria Parasites. Cell Host Microbe 2012; 12:824-34. [PMID: 23245327 PMCID: PMC3712325 DOI: 10.1016/j.chom.2012.10.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 09/10/2012] [Accepted: 10/12/2012] [Indexed: 11/25/2022]
Abstract
A major obstacle in analyzing gene function in apicomplexan parasites is the absence of a practical regulatable expression system. Here, we identified functional transcriptional activation domains within Apicomplexan AP2 (ApiAP2) family transcription factors. These ApiAP2 transactivation domains were validated in blood-, liver-, and mosquito-stage parasites and used to create a robust conditional expression system for stage-specific, tetracycline-dependent gene regulation in Toxoplasma gondii, Plasmodium berghei, and Plasmodium falciparum. To demonstrate the utility of this system, we created conditional knockdowns of two essential P. berghei genes: profilin (PRF), a protein implicated in parasite invasion, and N-myristoyltransferase (NMT), which catalyzes protein acylation. Tetracycline-induced repression of PRF and NMT expression resulted in a dramatic reduction in parasite viability. This efficient regulatable system will allow for the functional characterization of essential proteins that are found in these important parasites.
Collapse
|
50
|
Oehring SC, Woodcroft BJ, Moes S, Wetzel J, Dietz O, Pulfer A, Dekiwadia C, Maeser P, Flueck C, Witmer K, Brancucci NMB, Niederwieser I, Jenoe P, Ralph SA, Voss TS. Organellar proteomics reveals hundreds of novel nuclear proteins in the malaria parasite Plasmodium falciparum. Genome Biol 2012. [PMID: 23181666 PMCID: PMC4053738 DOI: 10.1186/gb-2012-13-11-r108] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The post-genomic era of malaria research provided unprecedented insights into the biology of Plasmodium parasites. Due to the large evolutionary distance to model eukaryotes, however, we lack a profound understanding of many processes in Plasmodium biology. One example is the cell nucleus, which controls the parasite genome in a development- and cell cycle-specific manner through mostly unknown mechanisms. To study this important organelle in detail, we conducted an integrative analysis of the P. falciparum nuclear proteome. RESULTS We combined high accuracy mass spectrometry and bioinformatic approaches to present for the first time an experimentally determined core nuclear proteome for P. falciparum. Besides a large number of factors implicated in known nuclear processes, one-third of all detected proteins carry no functional annotation, including many phylum- or genus-specific factors. Importantly, extensive experimental validation using 30 transgenic cell lines confirmed the high specificity of this inventory, and revealed distinct nuclear localization patterns of hitherto uncharacterized proteins. Further, our detailed analysis identified novel protein domains potentially implicated in gene transcription pathways, and sheds important new light on nuclear compartments and processes including regulatory complexes, the nucleolus, nuclear pores, and nuclear import pathways. CONCLUSION Our study provides comprehensive new insight into the biology of the Plasmodium nucleus and will serve as an important platform for dissecting general and parasite-specific nuclear processes in malaria parasites. Moreover, as the first nuclear proteome characterized in any protist organism, it will provide an important resource for studying evolutionary aspects of nuclear biology.
Collapse
|