scholarly journals Small-Subunit rRNA Processome Proteins Are Translationally Regulated during Differentiation of Trypanosoma cruzi

2006 ◽  
Vol 6 (2) ◽  
pp. 337-345 ◽  
Author(s):  
Sheila Cristina Nardelli ◽  
Andréa Rodrigues Ávila ◽  
Aline Freund ◽  
Maria Cristina Motta ◽  
Lauro Manhães ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Trypanosoma Cruzi ◽  
Sucrose Gradient ◽  
Protozoan Parasite ◽  
Small Subunit ◽  
Small Subunit Rrna ◽  
Translation Elongation ◽  
Metacyclic Trypomastigotes ◽  
Ssu Processome ◽  
Polysome Fraction

ABSTRACT We used differential display to select genes differentially expressed during differentiation of epimastigotes into metacyclic trypomastigotes in the protozoan parasite Trypanosoma cruzi. One of the selected clones had a sequence similar to that of the small-subunit (SSU) processome protein Sof1p, which is involved in rRNA processing. The corresponding T. cruzi protein, TcSof1, displayed a nuclear localization and is downregulated during metacyclogenesis. Heterologous RNA interference assays showed that depletion of this protein impaired growth but did not affect progression through the cell cycle, suggesting that ribosome synthesis regulation and the cell cycle are uncoupled in this parasite. Quantitative PCR (qPCR) assays of several SSU processome-specific genes in T. cruzi also showed that most of them were regulated posttranscriptionally. This process involves the accumulation of mRNA in the polysome fraction of metacyclic trypomastigotes, where TcSof1 cannot be detected. Metacyclic trypomastigote polysomes were purified and separated by sucrose gradient sedimentation. Northern blot analysis of the sucrose gradient fractions showed the association of TcSof1 mRNA with polysomes, confirming the qPCR data. The results suggest that the mechanism of regulation involves the blocking of translation elongation and/or termination.

scholarly journals The Small Subunit Processome Is Required for Cell Cycle Progression at G1

2004 ◽  
Vol 15 (11) ◽  
pp. 5038-5046 ◽  
Author(s):  
Kara A. Bernstein ◽  
Susan J. Baserga
Keyword(s):  
Cell Cycle ◽  
Ribosome Biogenesis ◽  
Cell Cycle Progression ◽  
Small Subunit ◽  
Cellular Growth ◽  
Yeast Cells ◽  
G1 Phase ◽  
Relay Cell ◽  
Ssu Processome ◽  
Nucleolar Rna

Without ribosome biogenesis, translation of mRNA into protein ceases and cellular growth stops. We asked whether ribosome biogenesis is cell cycle regulated in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, and we determined that it is not regulated in the same manner as in metazoan cells. We therefore turned our attention to cellular sensors that relay cell size information via ribosome biogenesis. Our results indicate that the small subunit (SSU) processome, a complex consisting of 40 proteins and the U3 small nucleolar RNA necessary for ribosome biogenesis, is not mitotically regulated. Furthermore, Nan1/Utp17, an SSU processome protein, does not provide a link between ribosome biogenesis and cell growth. However, when individual SSU processome proteins are depleted, cells arrest in the G1 phase of the cell cycle. This arrest was further supported by the lack of staining for proteins expressed in post-G1. Similarly, synchronized cells depleted of SSU processome proteins did not enter G2. This suggests that when ribosomes are no longer made, the cells stall in the G1. Therefore, yeast cells must grow to a critical size, which is dependent upon having a sufficient number of ribosomes during the G1 phase of the cell cycle, before cell division can occur.

Detection and identification ofEntamoeba gingivalisby specific amplification of rRNA gene

1996 ◽  
Vol 42 (12) ◽  
pp. 1248-1251 ◽  
Author(s):  
Noriko Kikuta ◽  
Ayako Yamamoto ◽  
Nobuichi Goto
Keyword(s):  
Polymerase Chain Reaction ◽  
Protozoan Parasite ◽  
Small Subunit ◽  
Rrna Gene ◽  
Small Subunit Rrna ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Detection And Identification ◽  
Specific Amplification ◽  
Polymerase Chain

A pair of oligonucleotide primers were designed from the nucleotide sequence of the gene encoding the small subunit ribosomal RNA (SrRNA) of the oral protozoan parasite Entamoeba gingivalis. The primers amplified a 1.4-kb DNA fragment by polymerase chain reaction and were specific for Entamoeba gingivalis but not for other protozoa, oral protists and bacteria, or human leukocytes. With this method, the DNA from as few as 30 cells of Entamoeba gingivalis could be detected. These results suggest that this approach is applicable to the detection and identification of Entamoeba gingivalis in the human oral cavity.Key words: Entamoeba gingivalis, small subunit rRNA, polymerase chain reaction, diagnostics.

Identification of a developmentally regulated iron superoxide dismutase of Trypanosoma brucei

2001 ◽  
Vol 360 (1) ◽  
pp. 173-177 ◽  
Author(s):  
Mostafa KABIRI ◽  
Dietmar STEVERDING
Keyword(s):  
Cell Cycle ◽  
Superoxide Dismutase ◽  
Trypanosoma Brucei ◽  
Protozoan Parasite ◽  
Small Subunit ◽  
Developmentally Regulated ◽  
Iron Superoxide Dismutase ◽  
Its Gene ◽  
Quantitative Changes ◽  
Post Transcriptional Regulation

An iron superoxide dismutase (FeSOD) gene of the protozoan parasite Trypanosoma brucei has been cloned and its gene product functionally characterized. The gene encodes a protein of 198 residues which shows 80% identity with FeSODs from other trypanosomatids. Inhibitor studies with purified recombinant FeSOD expressed in Escherichia coli confirmed that the enzyme is an iron-containing SOD. The FeSOD is developmentally regulated in the parasite, expression being lowest in the cell-cycle-arrested, short stumpy bloodstream forms. Differential expression of the FeSOD protein contrasts with only minor quantitative changes in the FeSOD mRNA, indicating post-transcriptional regulation of the enzyme. As the level of FeSOD increases during differentiation of cell-cycle-arrested short stumpy into dividing procyclic forms, it is suggested that the enzyme is only required in proliferating stages of the parasite for the elimination of superoxide radicals which are released during the generation of the iron-tyrosyl free-radical centre in the small subunit of ribonucleotide reductase.

Description of Ambrosiozyma oregonensis sp. nov., and reassignment of Candida species of the Ambrosiozyma clade to Ambrosiozyma kashinagacola f.a., comb. nov., Ambrosiozyma llanquihuensis f.a., comb. nov., Ambrosiozyma maleeae f.a., comb. nov., Ambrosiozyma pseudovanderkliftii f.a., comb. nov., and Ambrosiozyma vanderkliftii f.a., comb. nov.

2013 ◽  
Vol 63 (Pt_10) ◽  
pp. 3877-3883 ◽  
Author(s):  
Cletus P. Kurtzman ◽  
Christie J. Robnett
Keyword(s):  
Rna Polymerase Ii ◽  
Large Subunit ◽  
Elongation Factor ◽  
Nuclear Gene ◽  
Small Subunit ◽  
Mountain Stream ◽  
Small Subunit Rrna ◽  
Translation Elongation ◽  
Phenotypic Characters ◽  
Large Subunit Rrna

Ambrosiozyma oregonensis sp. nov. is described from two strains, one isolated from a mountain stream in Oregon, USA (NRRL Y-6106T = CBS 5560T), and a second (NRRL YB-4169) from an unknown substrate from Marion, Illinois, USA. The species forms four hat-shaped ascospores in each deliquescent ascus and appears to be homothallic. Abundant true hyphae are produced with some having apparent dolipore-like septa. Analyses of nuclear gene sequences for the D1/D2 domains of large-subunit rRNA, small-subunit rRNA, translation elongation factor-1α, and subunits B1 and B2 of RNA polymerase II show the proposed novel species to be distinct from other species of the Ambrosiozyma clade. Because of their placement in the Ambrosiozyma clade, Candida kashinagacola, Candida llanquihuensis, Candida maleeae, Candida pseudovanderkliftii and Candida vanderkliftii are reassigned to the genus Ambrosiozyma as new combinations, and the description of the genus Ambrosiozyma is emended to reflect the resulting changes in phenotypic characters.

scholarly journals First Detection of Cryptosporidium spp. in Migratory Whooper Swans (Cygnus cygnus) in China

2019 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Ke Wang ◽  
Azhar Gazizova ◽  
Yuexin Wang ◽  
Kaihui Zhang ◽  
Yifan Zhang ◽  
...  
Keyword(s):  
Sequence Data ◽  
Protozoan Parasite ◽  
Gastrointestinal Diseases ◽  
Small Subunit ◽  
Cryptosporidium Species ◽  
Small Subunit Rrna ◽  
Rrna Sequence ◽  
Cryptosporidium Spp ◽  
Cryptosporidium Andersoni ◽  
Positive Rate

Cryptosporidium is an important protozoan parasite that can cause gastrointestinal diseases in humans and that also causes respiratory and gastrointestinal diseases in birds. In this study, we investigated the occurrence of Cryptosporidium species in migratory whooper swans in China. Fecal samples (n = 467) from whooper swans were collected from Sanmenxia Swan Lake National Urban Wetland Park, China. The samples were analyzed for Cryptosporidium species and genotypes with PCR along a sequence analysis of the small subunit rRNA. Cryptosporidium was detected in eight of the 467 (1.7%) samples. The analysis of the small subunit rRNA sequence data revealed two zoonotic species (Cryptosporidium parvum and Cryptosporidium andersoni) and one genotype (Cryptosporidium goose genotype II). These are the first data on the positive rate of Cryptosporidium spp. in whooper swans in China, and they suggest that whooper swans can harbor the zoonotic species C. parvum and C. andersoni in China.

Reactivation of a Trypanosoma cruzi Infection in a Rhesus Monkey (Macaca mulatta) Experimentally Infected with SIV

2002 ◽  
Vol 39 (6) ◽  
pp. 721-725 ◽  
Author(s):  
E. Kunz ◽  
K. Mätz-Rensing ◽  
N. Stolte ◽  
P. B. Hamilton ◽  
F.-J. Kaup
Keyword(s):  
Trypanosoma Cruzi ◽  
Rhesus Monkey ◽  
Clinical Symptoms ◽  
Small Subunit ◽  
Rrna Gene ◽  
Small Subunit Rrna ◽  
Blood Smears ◽  
Immunodeficiency Virus ◽  
Siv Infection ◽  
Cruzi Infection

Trypanosoma cruzi-like flagellates were incidentally noted in blood smears of a routinely monitored rhesus monkey experimentally infected with the simian immunodeficiency virus (SIV). Immunodeficiency in the course of the SIV infection reactivated a chronic infection of Chagas' disease that had been unnoticed when the macaque was imported to Europe. The animal developed no specific clinical symptoms of American trypanosomiasis, but histologically a chagasic myocarditis was detected. Analysis of the small subunit rRNA gene of the trypanosome identified the protozoan as T. cruzi.

scholarly journals Citeromyces hawaiiensis sp. nov., an ascosporic yeast associated with Myoporum sandwicense

2012 ◽  
Vol 62 (Pt_5) ◽  
pp. 1215-1219 ◽  
Author(s):  
Cletus P. Kurtzman
Keyword(s):  
Large Subunit ◽  
Elongation Factor ◽  
Small Subunit ◽  
Small Subunit Rrna ◽  
Elongation Factor 1Α ◽  
Translation Elongation ◽  
Additional Strain ◽  
Adjacent Soil ◽  
Large Subunit Rrna ◽  
Translation Elongation Factor 1Α

Citeromyces hawaiiensis sp. nov. (NRRL Y-11581T  = CBS 12303T, type strain) is described from 12 strains isolated from flux of the sandalwood (Myoporum sandwicense) and adjacent soil in Hawaii, USA. Analyses of gene sequences from the D1/D2 domains of nuclear large subunit rRNA, internal transcribed spacer (ITS), mitochondrial small-subunit rRNA and translation elongation factor-1α each separated the proposed novel species from Citeromyces matritensis and Citeromyces siamensis, the other known species of the genus Citeromyces. The three species are morphologically similar but they can be separated by growth reactions in standard assimilation tests. An additional strain of Citeromyces siamensis (NRRL Y-11788), a species previously known only from Thailand, was obtained from spoiled condensed milk in Ohio, USA.

Phylogenetic classification and generic delineation of Hydeomyces desertipleosporoides gen. et sp. nov., (Phaeosphaeriaceae) from Jebel Akhdar Mountain in Oman

Phytotaxa ◽  
2019 ◽  
Vol 391 (1) ◽  
pp. 28 ◽  
Author(s):  
SAJEEWA S. N. MAHARACHCHIKUMBURA ◽  
HIRAN A. ARIYAWANSA ◽  
DHANUSHKA N. WANASINGHE ◽  
MONIKA C. DAYARATHNE ◽  
NADIYA A. AL-SAADY ◽  
...  
Keyword(s):  
Large Subunit ◽  
Elongation Factor ◽  
Small Subunit ◽  
Internal Transcribed Spacers ◽  
New Taxon ◽  
Small Subunit Rrna ◽  
Translation Elongation ◽  
The Family ◽  
Large Subunit Rrna ◽  
Elongation Factor 1

Specimens of a new pleosporalean taxon were obtained on the bark of Juniperus excels from the northern mountains of Oman; from the Jebel Akhdar (‘Green Hills’). Sequence analyses based on the regions of large subunit rRNA (LSU), small subunit rRNA (SSU), translation elongation factor 1-α (TEF) and internal transcribed spacers (ITS) were performed to resolve the phylogenetic relationships of the new taxon in Phaeosphaeriaceae. The data concluded that the taxon represents a novel genus of the family Phaeosphaeriaceae and the generic name Hydeomyces and the species name H. desertipleosporoides are introduced for the new taxon. An outline of the characters which differentiate the new genus from phylogenetically closely related genera Dematiopleospora and Dlhawksworthia is given and its morphology of asexual and sexual morphs is described.

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