scholarly journals Characterization of the Novel Mitochondrial Genome Segregation Factor TAP110 in Trypanosoma brucei

2021 ◽  
pp. jcs.254300
Author(s):  
Simona Amodeo ◽  
Ana Kalichava ◽  
Albert Fradera-Sola ◽  
Eloïse Bertiaux-Lequoy ◽  
Paul Guichard ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Trypanosoma Brucei ◽  
Proteome Analysis ◽  
Protozoan Parasite ◽  
Eukaryotic Cell ◽  
The Novel ◽  
Precise Position ◽  
Associated Proteins ◽  
First Time

Proper mitochondrial genome inheritance is important for eukaryotic cell survival. Trypanosoma brucei, a protozoan parasite, contains a singular mitochondrial genome, the kDNA. The kDNA is anchored to the basal body via the tripartite attachment complex (TAC) to ensure proper segregation. Several components of the TAC have been described. However, the connection of the TAC to the kDNA remains elusive. Here, we characterize the TAC associated protein TAP110. Depletion as well as overexpression of TAP110 leads to a delay in the separation of the replicated kDNA networks. Proteome analysis after TAP110 overexpression identified several kDNA associated proteins including a TEX-like protein that dually localizes to the nucleus and the kDNA potentially linking replication/segregation in the two compartments. The assembly of TAP110 into the TAC region seems to require the TAC but not the kDNA itself, however once TAP110 has been assembled it also interacts with the kDNA. Finally, for the first time we use ultrastructure expansion microscopy in trypanosomes to reveal the precise position of TAP110 between TAC102 and the kDNA, showcasing the potential of this approach.

scholarly journals Characterization of the Novel Mitochondrial Genome Segregation Factor TAP110 in Trypanosoma brucei

2020 ◽  
Author(s):  
Simona Amodeo ◽  
Ana Kalichava ◽  
Albert Fradera-Sola ◽  
Eloïse Bertiaux-Lequoy ◽  
Paul Guichard ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Trypanosoma Brucei ◽  
Protozoan Parasite ◽  
Eukaryotic Cell ◽  
The Novel ◽  
Detergent Treatment ◽  
Summary Statement ◽  
First Time

AbstractProper mitochondrial genome inheritance is key for eukaryotic cell survival, however little is known about the molecular mechanism controlling this process. Trypanosoma brucei, a protozoan parasite, contains a singular mitochondrial genome aka kinetoplast DNA (kDNA). kDNA segregation requires anchoring of the genome to the basal body via the tripartite attachment complex (TAC). Several components of the TAC as well as their assembly have been described, it however remains elusive how the TAC connects to the kDNA. Here, we characterize the TAC associated protein TAP110 and for the first time use ultrastructure expansion microscopy in trypanosomes to reveal that TAP110 is the currently most proximal kDNA segregation factor. The kDNA proximal positioning is also supported by RNAi depletion of TAC102, which leads to loss of TAP110 at the TAC. Overexpression of TAP110 leads to expression level changes of several mitochondrial proteins and a delay in the separation of the replicated kDNA networks. In contrast to other kDNA segregation factors TAP110 remains only partially attached to the flagellum after DNAse and detergent treatment and can only be solubilized in dyskinetoplastic cells, suggesting that interaction with the kDNA might be important for stability of the TAC association. Furthermore, we demonstrate that the TAC, but not the kDNA, is required for correct TAP110 localization in vivo and suggest that TAP110 might interact with other proteins to form a >669 kDa complex.Summary StatementTAP110 is a novel mitochondrial genome segregation factor in Trypanosoma brucei that associates with the previously described TAC component TAC102. Ultrastructure expansion microscopy reveals its proximal position to the kDNA.

scholarly journals Characterization of the Novel Mitochondrial Genome Replication Factor MiRF172 in Trypanosoma brucei

2017 ◽  
Author(s):  
Simona Amodeo ◽  
Martin Jakob ◽  
Torsten Ochsenreiter
Keyword(s):  
Mitochondrial Genome ◽  
Trypanosoma Brucei ◽  
Super Resolution ◽  
Genome Replication ◽  
The Novel ◽  
Replication Factor ◽  
Summary Statement ◽  
Super Resolution Microscopy ◽  
Novel Protein

AbstractThe unicellular parasite Trypanosoma brucei harbors one individual mitochondrial organelle with a singular genome the kinetoplast DNA or kDNA. The kDNA largely consists of concatenated minicircles and a few maxicircles that are also interlocked into the kDNA disc. More than 30 proteins involved in kDNA replication have been described, however several mechanistic questions are only poorly understood. Here, we describe and characterize MiRF172, a novel mitochondrial genome replication factor, which is essential for proper cell growth and kDNA maintenance. Using super-resolution microscopy, we localize MiRF172 to the antipodal sites of the kDNA. We demonstrate that depletion of MiRF172 leads to continuous loss of mini- and maxicircles during the cell division cycle. Detailed analysis suggests that MiRF172 is likely involved in the reattachment of replicated minicircles to the kDNA disc. Furthermore, we provide evidence that the localization of the replication factor MiRF172 not only depends on the kDNA itself, but also on the mitochondrial genome segregation machinery suggesting a tight interaction between the two essential entities.Summary StatementMiRF172 is a novel protein involved in the reattachment of replicated minicircles in Trypanosoma brucei, which requires the mitochondrial segregation machinery for proper localization.

scholarly journals Molecular Characterization of the Gene Encoding a New AmpC β-Lactamase in a Clinical Strain of Acinetobacter Genomic Species 3

2004 ◽  
Vol 48 (4) ◽  
pp. 1374-1378 ◽  
Author(s):  
Alejandro Beceiro ◽  
Lourdes Dominguez ◽  
Anna Ribera ◽  
Jordi Vila ◽  
Francisca Molina ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Molecular Characterization ◽  
Biochemical Properties ◽  
Clinical Strain ◽  
The Novel ◽  
Gene Encoding ◽  
Genomic Species ◽  
First Time

ABSTRACT A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this β-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC β-lactamase are reported

High-resolution crystal structure of Trypanosoma brucei pteridine reductase 1 in complex with an innovative tricyclic-based inhibitor

2020 ◽  
Vol 76 (6) ◽  
pp. 558-564
Author(s):  
Giacomo Landi ◽  
Pasquale Linciano ◽  
Giusy Tassone ◽  
Maria Paola Costi ◽  
Stefano Mangani ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Neglected Tropical Diseases ◽  
Protozoan Parasite ◽  
Binding Mode ◽  
New Class ◽  
Hydrogen Bond Interactions ◽  
Promising Strategy ◽  
Trypanosomatid Parasites ◽  
Micromolar Range

The protozoan parasite Trypanosoma brucei is the etiological agent of human African trypanosomiasis (HAT). HAT, together with other neglected tropical diseases, causes serious health and economic issues, especially in tropical and subtropical areas. The classical antifolates targeting dihydrofolate reductase (DHFR) are ineffective towards trypanosomatid parasites owing to a metabolic bypass by the expression of pteridine reductase 1 (PTR1). The combined inhibition of PTR1 and DHFR activities in Trypanosoma parasites represents a promising strategy for the development of new effective treatments for HAT. To date, only monocyclic and bicyclic aromatic systems have been proposed as inhibitors of T. brucei PTR1 (TbPTR1); nevertheless, the size of the catalytic cavity allows the accommodation of expanded molecular cores. Here, an innovative tricyclic-based compound has been explored as a TbPTR1-targeting molecule and its potential application for the development of a new class of PTR1 inhibitors has been evaluated. 2,4-Diaminopyrimido[4,5-b]indol-6-ol (1) was designed and synthesized, and was found to be effective in blocking TbPTR1 activity, with a K i in the low-micromolar range. The binding mode of 1 was clarified through the structural characterization of its ternary complex with TbPTR1 and the cofactor NADP(H), which was determined to 1.30 Å resolution. The compound adopts a substrate-like orientation inside the cavity that maximizes the binding contributions of hydrophobic and hydrogen-bond interactions. The binding mode of 1 was compared with those of previously reported bicyclic inhibitors, providing new insights for the design of innovative tricyclic-based molecules targeting TbPTR1.

scholarly journals Characterization of the inositol phosphorylceramide synthase activity from Trypanosoma cruzi

2005 ◽  
Vol 387 (2) ◽  
pp. 519-529 ◽  
Author(s):  
Juliana M. FIGUEIREDO ◽  
Wagner B. DIAS ◽  
Lucia MENDONÇA-PREVIATO ◽  
José O. PREVIATO ◽  
Norton HEISE
Keyword(s):  
Trypanosoma Cruzi ◽  
Inositol Phosphate ◽  
Protozoan Parasite ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Life Cycle Stages ◽  
Aureobasidin A ◽  
Triton X ◽  
First Time

IPC (inositol phosphorylceramide) synthase is an enzyme essential for fungal viability, and it is the target of potent antifungal compounds such as rustmicin and aureobasidin A. Similar to fungi and some other lower eukaryotes, the protozoan parasite Trypanosoma cruzi is capable of synthesizing free or protein-linked glycoinositolphospholipids containing IPC. As a first step towards understanding the importance and mechanism of IPC synthesis in T. cruzi, we investigated the effects of rustmicin and aureobasidin A on the proliferation of different life-cycle stages of the parasite. The compounds did not interfere with the axenic growth of epimastigotes, but aureobasidin A decreased the release of trypomastigotes from infected murine peritoneal macrophages and the number of intracellular amastigotes in a dose-dependent manner. We have demonstrated for the first time that all forms of T. cruzi express an IPC synthase activity that is capable of transferring inositol phosphate from phosphatidylinositol to the C-1 hydroxy group of C6-NBD-cer {6-[N-(7-nitro-2,1,3-benzoxadiazol-4-yl)-amino]hexanoylceramide} to form inositol phosphoryl-C6-NBD-cer, which was purified and characterized by its chromatographic behaviour on TLC and HPLC, sensitivity to phosphatidylinositol-specific phospholipase C and resistance to mild alkaline hydrolysis. Unlike the Saccharomyces cerevisiae IPC synthase, the T. cruzi enzyme is stimulated by Triton X-100 but not by bivalent cations, CHAPS or fatty-acid-free BSA, and it is not inhibited by rustmicin or aureobasidin A, or the two in combination. Further studies showed that aureobasidin A has effects on macrophages independent of the infecting T. cruzi cells. These results suggest that T. cruzi synthesizes its own IPC, but by a mechanism that is not affected by rustmicin and aureobasidin A.

scholarly journals Isolation and Characterization of a New Subtype of Borna Disease Virus

2000 ◽  
Vol 74 (12) ◽  
pp. 5655-5658 ◽  
Author(s):  
Norbert Nowotny ◽  
Jolanta Kolodziejek ◽  
Christian O. Jehle ◽  
Angelika Suchy ◽  
Peter Staeheli ◽  
...  
Keyword(s):  
Disease Virus ◽  
Single Type ◽  
The Novel ◽  
Borna Disease Virus ◽  
Diagnostic Assays ◽  
Isolation And Characterization ◽  
First Time ◽  
Reference Strains ◽  
Borna Disease

ABSTRACT Borna disease virus (BDV), the causative agent of severe meningoencephalitis in a wide variety of animal species, has been considered to be genetically invariable and to form a single type within the genus Bornavirus of the familyBornaviridae. BDV infections are of particular interest, because for the first time a virus infection appears to be linked to human psychiatric disorders. We now describe a new subtype of BDV isolated from a horse which was euthanatized due to severe, incurable neurological disease. The nucleotide sequence of this new strain, named No/98, differs from the reference strains by more than 15%, and the subtype is difficult to detect by standard reverse transcriptase PCR protocols. The nucleotide exchanges of the novel BDV isolate have surprisingly little effect on the primary structures of most viral proteins, with the notable exception of the X protein (p10), which is only 81% identical to its counterpart in reference strains. Our data indicate that the genome of BDV is far more variable than previously assumed and that naturally occurring subtypes may escape detection by currently used diagnostic assays.

scholarly journals Characterization of the novel mitochondrial genome replication factor MiRF172 inTrypanosoma brucei

2018 ◽  
Vol 131 (8) ◽  
pp. jcs211730 ◽  
Author(s):  
Simona Amodeo ◽  
Martin Jakob ◽  
Torsten Ochsenreiter
Keyword(s):  
Mitochondrial Genome ◽  
Genome Replication ◽  
The Novel ◽  
Replication Factor
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