Analýza genomu volně žijící améby Mastigamoeba balamuthi a porovnání s patogenní amébou Entamoeba histolytica

Charles University, Faculty of Science Department of parasitology Doctoral study programme: Parasitology Abstract (en) Analysis of the genome of a free-living amoeba Mastigamoeba balamuthi and its comparison with pathogenic Entamoeba histolytica Mgr. Vojtěch Žárský Supervisor: prof. RNDr. Jan Tachezy, Ph.D. Praha, 2020 Abstract Examination and comparison of organisms have been tremendously important for the study of life's history on earth. The progress of our understanding of the genetic basis of heredity and the recent boom of sequencing technologies allows us to continue in this exciting field of research from the perspective of genes and genomes. In this work, I focus on the study of an anaerobic amoeba Mastigamoeba balamuthi, which is related to an important human pathogen Entamoeba histolytica. Comparative analysis allows us to draw some conclusions about the nature of the common ancestor of Mastigamoeba and E. histolytica, how it adapted to the anaerobic lifestyle, and about the way the Entamoeba lineage evolved to become a successful parasite. Surprisingly we also noticed that besides hydrogenosomes (hydrogen-producing organelles related to mitochondria), M. balamuthi also harbors peroxisomes - organelles thought to be absent in anaerobic organisms. This finding motivated us to inquire more about...Univerzita Karlova, Přírodovědecká fakulta Katedra parazitologie Doktorský studijní program: Parazitologie Abstrakt (cz) Analýza genomu volně žijící améby Mastigamoeba balamuthi a porovnání s patogenní amébou Entamoeba histolytica Mgr. Vojtěch Žárský Školitel: prof. RNDr. Jan Tachezy, Ph.D. Praha, 2020 Abstrakt Výzkum a srovnávání organismů byly nesmírně významné pro studium historie života na Zemi. Pokrok v porozumění genetickému základu dědičnosti a nebývalý rozvoj sekvenačních technologií nám umožňuje pokračovat na tomto vzrušujícím poli výzkumu z perspektivy genů a genomů. V této práci se zaměřuji na studium anaerobní améby Mastigamoeba balamuthi, která je příbuzná významnému lidskému parazitu Entamoeba histolytica. Srovnávací analýza nám umožnila učinit některé závěry o vlastnostech společného předka M. balamuthi a E. histolytica, jak se přizpůsobil životu bez kyslíku, a jak se linie Entamoeba vyvinula v úspěšného parazita. Zjistili jsme přitom překvapivě, že vedle hydrogenosomů (odvozené mitochondrie produkující vodík) má M. balamuthi také peroxisomy - organely o kterých se soudilo, že je anaerobní organismy ztratily. Tento objev nás podnítil ke studiu distribuce peroxisomů u dalších eukaryotických linií. Zjistili jsme, že i u některých druhů Entamoeba nalézáme redukovaný soubor proteinů typických pro...Department of ParasitologyKatedra parazitologiePřírodovědecká fakultaFaculty of Scienc

Import proteinů do mitochondrií a peroxisomů parazitických prvoků

Předkládaná práce vychází ze tří projektů, kterým je společný zájem o evoluci eukaryotických organel a molekulárních systémů importu proteinů. První projekt poukazuje na možnost, že se peroxisomy (typické organely aerobních eukaryot) zachovaly u anaerobní skupiny Archamoebae, která zahrnuje parazita Entamoeba histolytica a volně žijícího prvoka Mastigamoeba balamuthi. Nejsilnějším vodítkem byl nález proteinů homologních ke známým komponentám peroxisomálního importu proteinů. Cílem druhého projektu je charakterizovat neznámou proteinovou translokázu vnitřní membrány mitosomů (redukovaných mitochondrií) u anaerobního prvoka Giardia intestinalis, kde se podařilo objevit podjednotku Tim44 této translokázy. Poslední projekt ukazuje, že translokáza vnější mitochondriální membrány trypanosomatid je příbuzná typické eukaryotické translokáze Tom40. Toto zjištění je důležité, neboť nepřítomnost Tom40 byla dříve považována za jeden z ancestrálních znaků trypanosomatid.The presented thesis includes three related projects, that are linked by a common interest in the evolution of eukaryotic organelles and machineries that import proteins into these compartments. The first project considers the possibility of peroxisomes (eukaryotic organelles known in aerobic organisms) being conserved in two related anaerobic protists: a free-living amoeba Mastigamoeba balamuthi and a parasite Entamoeba histolytica. The most important hint for the presence of peroxisomes was the discovery of proteins that are homologous to known components of the peroxisomal protein import machinery. The second project aims to characterize the unknown protein translocase of the inner membrane (TIM) in the mitosomes (extremely reduced mitochondria) of an anaerobic protozoan Giardia intestinalis. We have discovered an important subunit of the mitosomal translocase (Tim44), which usually tethers the Hsp70/PAM (presequence translocase-associated motor) complex to the TIM translocon. The last project shows that the protein translocase of the outer mitochondrial membrane in trypanosomatids is related to a typical eukaryotic channel Tom40. This finding is important because the absence of Tom40 was previously considered an ancestral feature of trypanosomatids.Department of ParasitologyKatedra parazitologieFaculty of SciencePřírodovědecká fakult

Analysis of diverse eukaryotes suggests the existence of an ancestral mitochondrial apparatus derived from the bacterial type II secretion system

The type 2 secretion system (T2SS) is present in some Gram-negative eubacteria and used to secrete proteins across the outer membrane. Here we report that certain representative heteroloboseans, jakobids, malawimonads and hemimastigotes unexpectedly possess homologues of core T2SS components. We show that at least some of them are present in mitochondria, and their behaviour in biochemical assays is consistent with the presence of a mitochondrial T2SS-derived system (miT2SS). We additionally identified 23 protein families co-occurring with miT2SS in eukaryotes. Seven of these proteins could be directly linked to the core miT2SS by functional data and/or sequence features, whereas others may represent different parts of a broader functional pathway, possibly also involving the peroxisome. Its distribution in eukaryotes and phylogenetic evidence together indicate that the miT2SS-centred pathway is an ancestral eukaryotic trait. Our findings thus have direct implications for the functional properties of the early mitochondrion

Evolution of eukaryotic ABC transporters

In the past twenty years there has been a lot of research done on ABC transporters. This group of membrane transporters was recognized as highly important due to its ubiquity in living organisms and due to the involvement of some of the ABC transporters in multidrug resistance of cancer cells and pathogens against chemotherapeutics. This medical aspect of ABC transporters was naturally the most important one for the majority of researchers. On the other hand, the biological aspects and evolution of many ABC transporters remained untouched. In this work I give an overview of ABC transporters of parasitic protozoa and focus on the evolutionary aspect of eukaryotic transporters and on mitochondrial ABC transporters, which are the most conserved ones among eukaryotic ABC transporters

Analysis of the genome of a free-living amoeba Mastigamoeba balamuthi and its comparison with pathogenic Entamoeba histolytica

Charles University, Faculty of Science Department of parasitology Doctoral study programme: Parasitology Abstract (en) Analysis of the genome of a free-living amoeba Mastigamoeba balamuthi and its comparison with pathogenic Entamoeba histolytica Mgr. Vojtěch Žárský Supervisor: prof. RNDr. Jan Tachezy, Ph.D. Praha, 2020 Abstract Examination and comparison of organisms have been tremendously important for the study of life's history on earth. The progress of our understanding of the genetic basis of heredity and the recent boom of sequencing technologies allows us to continue in this exciting field of research from the perspective of genes and genomes. In this work, I focus on the study of an anaerobic amoeba Mastigamoeba balamuthi, which is related to an important human pathogen Entamoeba histolytica. Comparative analysis allows us to draw some conclusions about the nature of the common ancestor of Mastigamoeba and E. histolytica, how it adapted to the anaerobic lifestyle, and about the way the Entamoeba lineage evolved to become a successful parasite. Surprisingly we also noticed that besides hydrogenosomes (hydrogen-producing organelles related to mitochondria), M. balamuthi also harbors peroxisomes - organelles thought to be absent in anaerobic organisms. This finding motivated us to inquire more about..

Protein import into mitochondria and peroxisomes of parasitic protists

The presented thesis includes three related projects, that are linked by a common interest in the evolution of eukaryotic organelles and machineries that import proteins into these compartments. The first project considers the possibility of peroxisomes (eukaryotic organelles known in aerobic organisms) being conserved in two related anaerobic protists: a free-living amoeba Mastigamoeba balamuthi and a parasite Entamoeba histolytica. The most important hint for the presence of peroxisomes was the discovery of proteins that are homologous to known components of the peroxisomal protein import machinery. The second project aims to characterize the unknown protein translocase of the inner membrane (TIM) in the mitosomes (extremely reduced mitochondria) of an anaerobic protozoan Giardia intestinalis. We have discovered an important subunit of the mitosomal translocase (Tim44), which usually tethers the Hsp70/PAM (presequence translocase-associated motor) complex to the TIM translocon. The last project shows that the protein translocase of the outer mitochondrial membrane in trypanosomatids is related to a typical eukaryotic channel Tom40. This finding is important because the absence of Tom40 was previously considered an ancestral feature of trypanosomatids

Additional file 4: Table S3. of Evolutionary loss of peroxisomes – not limited to parasites

Table of putative peroxisomal enzymes and the prediction of their localization. (XLS 7288 kb

Additional file 4: Table S2. of Evolution of the Tim17 protein family

The overall distribution of Tim17 family protein in eukaryotes. (XLS 135 kb

Additional file 6: Table S4. of Evolution of the Tim17 protein family

Prokaryotic proteins carrying a PRAT motif [(G/A)X2(F/Y)X10RX3DX6(G/A/S)GX3G]. (PDF 133 kb