Download or read book Identification and Functional Analysis of Proteins Involved in Host Cell Cytosol Uptake of the Human Malaria Parasite Plasmodium Falciparum written by Ricarda Sabitzki and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Proteins Involved in Host Cell Cytosol Uptake in the Human Malaria Parasite Plasmodium Falciparum written by Ernst Georg Wolfgang Jonscher and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Shock Proteins of Malaria written by Addmore Shonhai and published by Springer Nature. This book was released on 2021-09-26 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition describes the role of heat shock proteins in the life cycle of malaria parasites, particularly in the context of intracellular parasite stages. Thoroughly revised, this work provides a general introduction to the structural and functional features of heat shock proteins with a special focus on their role as molecular chaperones in ensuring protein quality control. The emphasis is on the heat shock protein families from Plasmodium falciparum, and their role in proteostasis and the development of malaria pathology. Moreover, the authors explore the latest prospects of targeting heat shock proteins in antimalarial drug discovery either directly or in combination therapies. Readers will experience a functional analysis of the individual families of heat shock proteins and their cooperation in functional networks, including both the parasite-resident proteome and the exportome released into host cells during intracellular stages. Subcellular and extracellular organelles such as the apicoplast and the Maurer’s Clefts associated with Plasmodium species are discussed in detail. The book highlights the role of heat shock proteins in the development and function of these structures. Biochemical expertise and the inclusion of novel therapeutic solutions make this collection a unique reference for experts in heat shock protein research, parasitology and infectious diseases, cell stress, molecular biology and drug discovery. Not least, advances in malaria control will contribute to ending epidemics and ensuring healthy lives in line with the UN Sustainable Development Goals.
Download or read book An Alternative Secretory Pathway in the Malaria Parasite Plasmodium falciparum written by Thuvaraka Thavayogarajah and published by GRIN Verlag. This book was released on 2017-08-31 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2014 in the subject Biology - Diseases, Health, Nutrition, grade: 1.3, University of Marburg (European virtual Institute for Malaria Research), language: English, abstract: This study focuses on the discovery of an alternative secretory pathway to the ER/Golgi route in the malaria parasite P. falciparum in infected RBCs. Two proteins appeared to be promising candidates of an alternative secretory pathway: the PfADP-ribosylation factor 1 (ARF1) and the Pfadenylate kinase 2 (AK2). Both proteins contained an N-myristoylation site at their N-terminus, which is indicative for N-myristoylation. N-myristoylation is a co-translational modification of a protein, whereby a fatty acid (myristate) is irreversibly attached to the glycine residue at the N-terminus of a protein via the PfN-myristoyltransferase (NMT). A preceding proteomic analysis of the parasitophorous vacuole and a reporter construct study proposed for both PfARF1 (determined by a proteomic study) and PfAK2 (determined by a reporter construct study) PV localization although both proteins lacked a signal peptide. That’s why it was hypothesized whether or not N-myristoylation would drive protein secretion across the parasite plasma membrane (PPM). The subcellular localization of the PfARF1/GFP parasites and the PfAK2/GFP parasites, respectively, were analyzed via epifluorescence microscopy and biochemical methods. In parallel, another batch of reporter constructs were generated and analyzed, where the N-myristoylation site of PfARF1 (this study) and PfAK2 (Ma et al., 2012), respectively, was removed (PfARF1G2A/GFP and PfAK2G2A/GFP). Live cell imaging showed that the fusion protein ARF1/GFP was localized as dot-like structures in the parasite. In contrast, the phenotype of the fusion protein of the PfARF1G2A/GFP parasites showed an evenly distributed signal in the parasite cytosol. Further analysis of the subcellular localization of the PfARF1 strongly supports its localization to compartments of the early secretory pathway of the parasite, but no localization in the PV. In contrast, the fusion protein PfAK2/GFP localized to a ring-like structure around the parasite indicating PV localization. The PfAK2G2A/GFP parasites showed a cytosolic localization of the fusion protein (Ma et al., 2012). Biochemical analyses revaled that the fusion protein PfAK2/GFP was secreted into the PV when the N-myristoylation site was present. Furthermore, it could be shown that the N-terminus of the PfAK2 protein is sufficient for parasite plasma membrane targeting, stable membrane anchoring and subsequent protein translocation across the PPM.
Download or read book Malaria written by Institute of Medicine and published by National Academies Press. This book was released on 1991-02-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Malaria is making a dramatic comeback in the world. The disease is the foremost health challenge in Africa south of the Sahara, and people traveling to malarious areas are at increased risk of malaria-related sickness and death. This book examines the prospects for bringing malaria under control, with specific recommendations for U.S. policy, directions for research and program funding, and appropriate roles for federal and international agencies and the medical and public health communities. The volume reports on the current status of malaria research, prevention, and control efforts worldwide. The authors present study results and commentary on the: Nature, clinical manifestations, diagnosis, and epidemiology of malaria. Biology of the malaria parasite and its vector. Prospects for developing malaria vaccines and improved treatments. Economic, social, and behavioral factors in malaria control.
Download or read book Malaria Parasites written by Andrew P. Waters and published by Caister Academic Press Limited. This book was released on 2004 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: The completion of the Plasmodium falciparum genome sequence in late 2002 heralded a new era in malaria research. The search began in earnest for new drugs and vaccines to combat malaria, a disease which afflicts up to 500 million people worldwide and is responsible for the deaths of more than one million people each year. The new genomic data is aiding a greater understanding of the living parasite and its interaction with the insect vector and human host. In this book internationally renowned experts provide up-to-date reviews of the most important aspects of post-genomic malaria research. Topics covered include: the P. falciparum genome and model parasites, bioinformatics and genome databases, microsatellite analysis, analysis of chromosome structure, cell cycle to RNA polymerase I and II mediated gene expression, role of the nuclear genome, the parasite surface and cell biology, and much more. The book is essential to all researchers working in this highly topical field and is recommended reading for scientists in other areas of biology and medicine.
Download or read book Models to study malaria parasite host cell interactions and pathogenesis written by Alister Craig and published by Frontiers Media SA. This book was released on 2022-11-07 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CryoEM Enabled Approaches to Structure Determination of Endogenous Protein Complexes Implicated in the Pathogenesis of the Malaria Parasite Plasmodium Falciparum written by Chi-Min Ho and published by . This book was released on 2019 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complexity and breadth of the host-cell remodeling machinery in the malaria parasite P. falciparum make it a rich and exciting system for the study of host-pathogen interfaces, particularly as many of the molecular mechanisms underlying this parasite's ability to hijack human red blood cells remain unclear. Furthermore, the P. falciparum proteome has proven recalcitrant to structural and biochemical characterization using recombinant methods, making it an intriguing model system for the development of new methods that leverage recent advances in cryoEM to enable structural studies of previously intractable systems at near-atomic resolution. The work presented here makes significant contributions in both these regards. First, we use a targeted, CRISPR-enabled "top down" approach to determine near-atomic resolution structures of the unique malaria parasite translocon PTEX, which we purified directly from P. falciparum parasites in multiple functional states, yielding the first near-atomic resolution cryoEM structures of a protein isolated directly from an endogenous source using an epitope tag inserted into the endogenous locus with CRISPR-Cas9 gene editing. We then developed a "bottom up" endogenous structural proteomics method whereby protein complexes enriched directly from the cellular milieu are identified by imaging and structure determination using cryoEM and mass spectrometry. As a proof of principle, we successfully used this approach to obtain near-atomic resolution structures of multiple protein complexes from the P. falciparum proteome, which has previously proven recalcitrant to expression in recombinant systems, precluding structure determination by X-ray crystallography or NMR. The body of work described here addresses a known need for methods that overcome the limitations of structural biology approaches that depend on recombinant systems, opening the door for high resolution structure determination of a vast number of previously intractable biological systems.
Download or read book World malaria report 2017 written by World Health Organization and published by World Health Organization. This book was released on 2018-02-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The World Malaria Report 2017 presents a comprehensive state of play in global progress in the fight against malaria up to the end of 2016. It tracks progress in investments in malaria programs and research, malaria prevention, diagnosis and treatment, surveillance, trends in malaria disease burden, malaria elimination, and threats in tackling malaria and safeguarding the investments made. The report draws on data from 91 countries and areas with ongoing malaria transmission. The information is supplemented by data from national household surveys and databases held by other organizations. This year's report shows that after an unprecedented period of success in global malaria control, progress has stalled. In 2016, there were an estimated 216 million cases of malaria, an increase of about 5 million cases over 2015. Deaths reached 445,000, a similar number to the previous year.
Download or read book A Novel Genetic System for the Functional Analysis of Essential Proteins of the Human Malaria Parasite Plasmodium Falciparum written by Jakob Birnbaum and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Plasmodium Falciparum Mitochondrial Proteome for Functional Analysis of Conserved Essential Proteins written by Ian Michael Lamb and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mitochondrial functions are essential throughout the life cycle of malaria parasites and are validated as targets of antimalarial drugs such as atovaquone. Using a mitochondrially targeted proximity biotinylation approach, here, we explore the possibility that identification of novel, conserved, and essential proteins encoding mitochondrial functions may provide additional targets for the discovery of antimalarial drugs in P. falciparum. To initiate this investigation, we generated parasites that express a protein where the Hsp60 leader sequence (for mitochondrial targeting) is fused to the promiscuous biotin ligase TurboID from an ectopic locus. Initial experiments suggested inefficient targeting to the mitochondrion, as many cytosolic proteins were identified in the mass spectrometry analysis, presumably due to labeling by Hsp60L-TurboID proteins in transit to the mitochondrion. To overcome this challenge, we employed hypotonic lysis and centrifugation to fractionate parasite pellets into "soluble" and "membrane" fractions after labeling. After three biological replicates of this experiment and subsequent mass spectrometry analysis, we identified 121 proteins that we considered to be "putative mitochondrial" proteins. Of these, 26 were annotated as conserved Plasmodium proteins of unknown function. We characterized five of these 122 for their sub-cellular localization and found that four were localized to the mitochondrion. Of these, PF3D7_0707400 attracted our attention as a candidate for phenotypic characterization. This protein is abundantly expressed and is an ortholog of mammalian ATAD3A (ATPase family AAA+ domain-containing protein 3), a mitochondrial membrane localized protein. In mammals, ATAD3A spans the matrix, the inner and outer mitochondrial membranes, and communicates with the endoplasmic reticulum, playing a central role in mitochondrial biogenesis. ATAD3A orthologues are conserved in all apicomplexans, including Cryptosporidium, suggesting it to have a critical role in mitochondrial physiology of all of these parasites. To initiate its characterization in malaria parasites, we generated parasites in which this protein was endogenously tagged and subjected to conditional expression. These parasites grew normally in the presence of aTc but failed to thrive in the absence of aTc within 72 hours. Mitochondrial membrane potential in PfATAD3A knockdown parasites was collapsed by 48 hours. Native gel electrophoresis suggested PfATAD3A to be a part of a complex estimated to be >5 million Dalton. Characterization of this complex will likely reveal hitherto unknown essential features of mitochondrial physiology in malaria parasites.
Download or read book Structure Function and Antibody mediated Inhibition of Plasmodium CelTOS a Protein that Enables Cell Traversal by Malaria Parasites written by John Rashid Jimah and published by . This book was released on 2017 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Malaria is an immense global health problem which is primarily caused by Plasmodium falciparum and Plasmodium vivax parasites. These parasites have a complex life cycle, with stages in the human host and mosquito vector, and traverse diverse host and vector cells. Cell traversal involves biological processes such as parasite motility, breaching of cell membranes, and immune evasion which are mediated by various Plasmodium proteins that are only now beginning to be identified. Genetic studies have implicated Plasmodium CelTOS (cell-traversal protein for ookinetes and sporozoites) in mediating the traversal of sporozoites through the mammalian liver sinusoidal layer and ookinetes through the mosquito midgut epithelium. Additionally, CelTOS is a promising malaria vaccine candidate, as immunization of mice with CelTOS elicits a protective humoral and cell-mediated immune response. An immune response to CelTOS in humans is also correlated with protection from malaria. Even though CelTOS has critical roles in Plasmodium biology and is a vaccine target, the molecular function and mechanism of CelTOS had been unknown, primarily due to its lack of sequence similarity to proteins of known function.In our studies, we investigated the biophysical function of CelTOS to gain insight into its role during cell traversal. We determined the structure of PvCelTOS and observed similarity to proteins that bind and disrupt cell membranes, including HIV-1 gp41 and the Mycobacterium toxin ESAT-6. The structural similarity of CelTOS to these proteins informed the hypothesis that CelTOS binds and disrupts host and vector cell plasma membranes to enable the exit of parasites out of invaded cells during traversal. Subsequent investigations revealed that CelTOS specifically binds phosphatidic acid, a lipid predominantly present within the inner leaflet of cell plasma membranes, and disrupts liposomes composed of this lipid by pore-formation. Furthermore, microinjection of CelTOS into Xenopus oocytes damaged the plasma membrane and resulted in leakage of the cytosol. Taken together, we have identified CelTOS as the first Plasmodium protein that enables the exit of malaria parasites from host and vector cells.Given that CelTOS enables the progression of parasites through stages in the mosquito vector and human host, it is a unique malaria vaccine candidate that may block both malaria transmission and infection. Immunization with CelTOS elicits antibodies that have been shown to inhibit malaria infection in mice. CelTOS antibodies also block ookinete development into oocysts, an important step in sporozoite development within mosquitoes. We investigated the mechanism of antibody-mediated inhibition of CelTOS by identifying the epitopes in CelTOS targeted by neutralizing and non-neutralizing antibodies. The crystal structures of CelTOS in complex with neutralizing antibodies delineate residues that are targeted by antibodies that block CelTOS-mediated membrane disruption. Identification of neutralizing epitopes in CelTOS will inform the design of immunogens that elicit potent neutralizing antibodies.In summary, our findings reveal CelTOS targets the inner leaflet of host and vector cell plasma membranes by pore formation which may enable the exit of parasites during cell traversal. Additionally, we have identified epitopes in Plasmodium CelTOS that are targeted by antibodies, which begins to elucidate the mechanism of antibody-mediated inhibition of CelTOS. These findings provide a foundation for exploring the biophysical mechanism of CelTOS including the mechanisms of lipid binding, membrane insertion, and oligomerization within membranes to form pores. Also, the approaches used in this study may be applied to elucidate the role of putative pore-forming proteins, such as SPECT2 and MAOP, which mediate other steps in cell traversal. Finally, by determining the structure of CelTOS and developing an in vitro method for testing CelTOS activity, this study will inform the design and screening of therapeutics and vaccines which target CelTOS to protect against malaria.
Download or read book Functional Analysis of Trophozoite and Schizont exported Proteins of the Human Malaria Parasite Plasmodium Falciparum Welch 1897 written by Jan Stäcker and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of the Protein Export Steps at the Parasite host Cell Interface of the Human Malaria Parasite Plasmodium Falciparum Welch 1897 written by Paolo Mesén-Ramírez and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of the Protein Export Steps at the Parasite host Cell Interface of the Human Malaria Parasite Plasmodium Falciparum Welch 1897 written by Paolo Mesén-Ramírez and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Protein Translocation at the Interface Between the Malaria Parasite Plasmodium Falciparum and Its Host Cell written by Ferdinand Reinsch and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation on the Trafficking of Haemoglobin Uptake Process in Plasmodium Falciparum Using Fluorescent Proteins written by Lina Rozana and published by . This book was released on 2009 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Malaria is a disease that claims nearly one million lives each year, with the most severe form of the disease caused by the protozoan parasite Plasmodium falcqmrum. This parasite invades human red blood cells and ingests approximately 75% of the host cell haemoglobin for its further development in the intraerythrocytic cycle. However, little is known about the parasite mode of haemoglobin uptake. A deeper understanding of this process may lead to the identification of possible strategies for the development of novel anti-malarial drugs. Electron microscopy studies by Elliott et al. (2008) suggested that there are four independent pathways for the parasite haemoglobin uptake process; however, research is limited by the inability to view this process in live cells. Therefore, this project attempts to identify the haemoglobin uptake process in live P. falczparum cells by confocal microscopy using fluorescent proteins as markers of the haemoglobin. These recombinant fluorescent proteins (DENDRA and EGFP) were expressed, purified and characterized before being resealed into erythrocytes, followed by parasite infection. Optimizations of the resealing experiments managed to narrow the concentration range of fluorescent proteins in the resealed RBC up to 70 uM. Images of the haemoglobin uptake process in live ring and trophozoite stage parasites were captured showing that the formation of haemoglobin-containing structures in the form of small vesicles and tubes is very active during the ring stages. The appearance of the proposed "Big Gulp" was not observed; instead, the ring stage parasites seem to be forming a cup-shaped position, suggesting that it may be an artefact. These observations could lead to further investigation of the haemoglobin uptake process in P. falczparum.
