TY  - JOUR
A1  - Reynolds, David
A1  - Cliffe, Laura
A1  - Förstner, Konrad U.
A1  - Hon, Chung-Chau
A1  - Siegel, T. Nicolai
A1  - Sabatini, Robert
T1  - Regulation of transcription termination by glucosylated hydroxymethyluracil, base J, in Leishmania major and Trypanosoma brucei
JF  - Nucleic Acids Research
N2  - Base J, beta-d-glucosyl-hydroxymethyluracil, is an epigenetic modification of thymine in the nuclear DNA of flagellated protozoa of the order Kinetoplastida. J is enriched at sites involved in RNA polymerase ( RNAP) II initiation and termination. Reduction of J in Leishmania tarentolae via growth in BrdU resulted in cell death and indicated a role of J in the regulation of RNAP II termination. To further explore J function in RNAP II termination among kinetoplastids and avoid indirect effects associated with BrdU toxicity and genetic deletions, we inhibited J synthesis in Leishmania major and Trypanosoma brucei using DMOG. Reduction of J in L. major resulted in genome-wide defects in transcription termination at the end of polycistronic gene clusters and the generation of antisense RNAs, without cell death. In contrast, loss of J in T. brucei did not lead to genome-wide termination defects; however, the loss of J at specific sites within polycistronic gene clusters led to altered transcription termination and increased expression of downstream genes. Thus, J regulation of RNAP II transcription termination genome-wide is restricted to Leishmania spp., while in T. brucei it regulates termination and gene expression at specific sites within polycistronic gene clusters.
KW  - RNA-polymerase-II
KW  - variant surface glycoprotein
KW  - SWI2/SNF2-like protein
KW  - messenger RNA
KW  - polycistronic transcription
KW  - DNA glycosation
KW  - hela cells
KW  - gene expression
KW  - genome
KW  - 5-bromodeoxyuridine
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117863
VL  - 42
IS  - 15
ER  - 
TY  - JOUR
A1  - Gross, Henrik
A1  - Hennard, Christine
A1  - Masouris, Ilias
A1  - Cassel, Christian
A1  - Barth, Stephanie
A1  - Stober-Grässer, Ute
A1  - Mamiani, Alfredo
A1  - Moritz, Bodo
A1  - Ostareck, Dirk
A1  - Ostareck-Lederer, Antje
A1  - Neuenkirchen, Nils
A1  - Fischer, Utz
A1  - Deng, Wen
A1  - Leonhardt, Heinrich
A1  - Noessner, Elfriede
A1  - Kremmer, Elisabeth
A1  - Grässer, Friedrich A.
T1  - Binding of the Heterogeneous Ribonucleoprotein K (hnRNP K) to the Epstein-Barr Virus Nuclear Antigen 2 (EBNA2) Enhances Viral LMP2A Expression
JF  - PLoS One
N2  - The Epstein-Barr Virus (EBV) -encoded EBNA2 protein, which is essential for the in vitro transformation of B-lymphocytes, interferes with cellular processes by binding to proteins via conserved sequence motifs. Its Arginine-Glycine (RG) repeat element contains either symmetrically or asymmetrically di-methylated arginine residues (SDMA and ADMA, respectively). EBNA2 binds via its SDMA-modified RG-repeat to the survival motor neurons protein (SMN) and via the ADMA-RG-repeat to the NP9 protein of the human endogenous retrovirus K (HERV-K (HML-2) Type 1). The hypothesis of this work was that the methylated RG-repeat mimics an epitope shared with cellular proteins that is used for interaction with target structures. With monoclonal antibodies against the modified RG-repeat, we indeed identified cellular homologues that apparently have the same surface structure as methylated EBNA2. With the SDMA-specific antibodies, we precipitated the Sm protein D3 (SmD3) which, like EBNA2, binds via its SDMA-modified RG-repeat to SMN. With the ADMA-specific antibodies, we precipitated the heterogeneous ribonucleoprotein K (hnRNP K). Specific binding of the ADMA-antibody to hnRNP K was demonstrated using E. coli expressed/ADMA-methylated hnRNP K. In addition, we show that EBNA2 and hnRNP K form a complex in EBV-infected B-cells. Finally, hnRNP K, when co-expressed with EBNA2, strongly enhances viral latent membrane protein 2A (LMP2A) expression by an unknown mechanism as we did not detect a direct association of hnRNP K with DNA-bound EBNA2 in gel shift experiments. Our data support the notion that the methylated surface of EBNA2 mimics the surface structure of cellular proteins to interfere with or co-opt their functional properties.
KW  - SM proteins
KW  - protein argentine methyltranserase
KW  - motor-neuron protein
KW  - RNA-polymerase-II
KW  - messenger RNA
KW  - C-MYC
KW  - gene expression
KW  - splicing factor
KW  - down regulation
KW  - living cells
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133707
VL  - 7
IS  - 8
ER  -