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Hofmeister B.T.,Institute of Bioinformatics | Siegel T.N.,Research Center for Infectious Diseases
Molecular Microbiology | Year: 2016

The genomes of kinetoplastids are organized into polycistronic gene clusters that are flanked by the modified DNA base J. Previous work has established a role of base J in promoting RNA polymerase II termination in Leishmania spp. where the loss of J leads to termination defects and transcription into adjacent gene clusters. It remains unclear whether these termination defects affect gene expression and whether read through transcription is detrimental to cell growth, thus explaining the essential nature of J. We now demonstrate that reduction of base J at specific sites within polycistronic gene clusters in L. major leads to read through transcription and increased expression of downstream genes in the cluster. Interestingly, subsequent transcription into the opposing polycistronic gene cluster does not lead to downregulation of sense mRNAs. These findings indicate a conserved role for J regulating transcription termination and expression of genes within polycistronic gene clusters in trypanosomatids. In contrast to the expectations often attributed to opposing transcription, the essential nature of J in Leishmania spp. is related to its role in gene repression rather than preventing transcriptional interference resulting from read through and dual strand transcription. © 2016 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd. Source


Chiang Y.-M.,Chia Nan University of Pharmacy and Science | Chiang Y.-M.,University of Southern California | Szewczyk E.,Ohio State University | Szewczyk E.,Research Center for Infectious Diseases | And 6 more authors.
Applied and Environmental Microbiology | Year: 2010

Deletion of cclA, a component of the COMPASS complex of Aspergillus nidulans, results in the production of monodictyphenone and emodin derivatives. Through a set of targeted deletions in a cclA deletion strain, we have identified the genes required for monodictyphenone and emodin analog biosynthesis. Identification of an intermediate, endocrocin, from an mdpHΔ strain suggests that mdpH might encode a decarboxylase. Furthermore, by replacing the promoter of mdpA (a putative aflJ homolog) and mdpE (a putative aflR homolog) with the inducible alcA promoter, we have confirmed that MdpA functions as a coactivator. We propose a bio synthetic pathway for monodictyphenone and emodin derivatives based on bioinformatic analysis and characterization of biosynthetic intermediates. Copyright © 2010, American Society for Microbiology. All Rights Reserved. Source


Lodige M.,University of Wurzburg | Lewis M.D.,University of Heidelberg | Paulsen E.S.,University of Wurzburg | Paulsen E.S.,Copenhagen University | And 7 more authors.
International Journal of Medical Microbiology | Year: 2013

We present a new class of hybrid molecules consisting of the established antiplasmodial drugs primaquine and chloroquine. No drug is known to date that acts comparably against all stages of Plasmodium in its life cycle. Starting from available precursors, we designed and synthesized a new-generation compound consisting of both primaquine and chloroquine components, with the intent to produce agents that exhibit bioactivity against different stages of the parasite's life cycle. In vitro, the hybrid molecule 3 displays activity against both asexual and sexual P. falciparum blood stages as well as P. berghei sporozoites and liver stages. In vivo, the hybrid elicits activity against P. berghei liver and blood stages. Our results successfully validate the concept of utilizing one compound to combine different modes of action that attack different Plasmodium stages in the mammalian host. It is our hope that the novel design of such compounds will outwit the pathogen in the spread of drug resistance. Based on the optimized synthetic pathway, the compound is accessible in a smooth and versatile way and open for potential further molecular modification. © 2013 Elsevier GmbH. Source


Gonzalez-Quintana V.,National Autonomous University of Mexico | Palma-Berre L.,National Autonomous University of Mexico | Campos-Parra A.D.,National Cancer Institute of Mexico | Lopez-Urrutia E.,National Autonomous University of Mexico | And 4 more authors.
Oncology Reports | Year: 2016

Cervical cancer (CC) is the third most diagnosed cancer among females worldwide and the fourth cause of cancer-related mortality. Prophylactic HPV vaccines and traditional pap-smear screening are undoubtedly capable of decreasing the incidence and mortality of CC. However, a large number of females succumb to the disease each year due to late diagnosis and resistance to conventional treatments. Thus, it is necessary to identify new molecular markers to predict the clinical outcome and to design powerful treatments. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and are involved in the modulation of several cell pathways associated with progression from pre-malignant to invasive and metastatic disease, increasing tumor malignancy. The aim of this review was to summarize the recent data that describe the important role of miRNAS involved in CC in order to determine their potential as prognostic biomarkers and as therapy targets. Studies of >40 miRNAs with roles in cancer regulation were identified. We also identified 17 miRNAs associated with progression, 12 involved with clinical outcome and 7 that improved CC treatment response. The present review is expected to broaden understanding of the functional role and potential clinical uses of miRNAs in CC. Source


Lioliou E.,University of Strasbourg | Sharma C.M.,Research Center for Infectious Diseases | Altuvia Y.,Hebrew University of Jerusalem | Caldelari I.,University of Strasbourg | And 4 more authors.
Methods | Year: 2013

Ribonucleases play key roles in gene regulation and in the expression of virulence factors in Staphylococcus aureus. Among these enzymes, the double-strand specific endoribonuclease III (RNase III) is a key mediator of mRNA processing and degradation. Recently, we have defined, direct target sites for RNase III processing on a genome-wide scale in S. aureus. Our approach is based on deep sequencing of cDNA libraries obtained from RNAs isolated by in vivo co-immunoprecipitation with wild-type RNase III and two cleavage-defective mutants. The use of such catalytically inactivated enzymes, which still retain their RNA binding capacity, allows the identification of novel RNA substrates of RNase III. In this report, we will summarize the diversity of RNase III functions, discuss the advantages and the limitations of the approach, and how this strategy identifies novel mRNA targets of small non-coding RNAs in S. aureus. © 2013 Elsevier Inc. Source

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