TY - JOUR A1 - Leal, Andrea Zurita A1 - Schwebs, Marie A1 - Briggs, Emma A1 - Weisert, Nadine A1 - Reis, Helena A1 - Lemgruber, Leondro A1 - Luko, Katarina A1 - Wilkes, Jonathan A1 - Butter, Falk A1 - McCulloch, Richard A1 - Janzen, Christian J. T1 - Genome maintenance functions of a putative Trypanosoma brucei translesion DNA polymerase include telomere association and a role in antigenic variation JF - Nucleic Acids Research N2 - Maintenance of genome integrity is critical to guarantee transfer of an intact genome from parent to off-spring during cell division. DNA polymerases (Pols) provide roles in both replication of the genome and the repair of a wide range of lesions. Amongst replicative DNA Pols, translesion DNA Pols play a particular role: replication to bypass DNA damage. All cells express a range of translesion Pols, but little work has examined their function in parasites, including whether the enzymes might contribute to host-parasite interactions. Here, we describe a dual function of one putative translesion Pol in African trypanosomes, which we now name TbPolIE. Previously, we demonstrated that TbPolIE is associated with telomeric sequences and here we show that RNAi-mediated depletion of TbPolIE transcripts results in slowed growth, altered DNA content, changes in cell morphology, and increased sensitivity to DNA damaging agents. We also show that TbPolIE displays pronounced localization at the nuclear periphery, and that its depletion leads to chromosome segregation defects and increased levels of endogenous DNA damage. Finally, we demonstrate that TbPolIE depletion leads to deregulation of telomeric variant surface glycoprotein genes, linking the function of this putative translesion DNA polymerase to host immune evasion by antigenic variation. KW - cross-link repair KW - cell cycle KW - gene expression KW - low fidelity KW - replication KW - bypass KW - theta KW - reveals KW - binding Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230579 VL - 48 IS - 17 ER - TY - JOUR A1 - Wolter, Patrick A1 - Hanselmann, Steffen A1 - Pattschull, Grit A1 - Schruf, Eva A1 - Gaubatz, Stefan T1 - Central spindle proteins and mitotic kinesins are direct transcriptional targets of MuvB, B-MYB and FOXM1 in breast cancer cell lines and are potential targets for therapy JF - Oncotarget N2 - The MuvB multiprotein complex, together with B-MYB and FOXM1 (MMB-FOXM1), plays an essential role in cell cycle progression by regulating the transcription of genes required for mitosis and cytokinesis. In many tumors, B-MYB and FOXM1 are overexpressed as part of the proliferation signature. However, the transcriptional targets that are important for oncogenesis have not been identified. Given that mitotic kinesins are highly expressed in cancer cells and that selected kinesins have been reported as target genes of MMB-FOXM1, we sought to determine which mitotic kinesins are directly regulated by MMB-FOXM1. We demonstrate that six mitotic kinesins and two microtubule-associated non-motor proteins (MAPs) CEP55 and PRC1 are direct transcriptional targets of MuvB, B-MYB and FOXM1 in breast cancer cells. Suppression of KIF23 and PRC1 strongly suppressed proliferation of MDA-MB-231 cells. The set of MMB-FOXM1 regulated kinesins genes and 4 additional kinesins which we referred to as the mitotic kinesin signature (MKS) is linked to poor outcome in breast cancer patients. Thus, mitotic kinesins could be used as prognostic biomarker and could be potential therapeutic targets for the treatment of breast cancer. KW - breast cancer KW - kinesin KW - cell cycle KW - cytokinesis Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171851 VL - 8 IS - 7 ER - TY - JOUR A1 - Gaubatz, Stefan A1 - Esterlechner, Jasmina A1 - Reichert, Nina A1 - Iltzsche, Fabian A1 - Krause, Michael A1 - Finkernagel, Florian T1 - LIN9, a Subunit of the DREAM Complex, Regulates Mitotic Gene Expression and Proliferation of Embryonic Stem Cells JF - PLoS ONE N2 - The DREAM complex plays an important role in regulation of gene expression during the cell cycle. We have previously shown that the DREAM subunit LIN9 is required for early embryonic development and for the maintenance of the inner cell mass in vitro. In this study we examined the effect of knocking down LIN9 on ESCs. We demonstrate that depletion of LIN9 alters the cell cycle distribution of ESCs and results in an accumulation of cells in G2 and M and in an increase of polyploid cells. Genome-wide expression studies showed that the depletion of LIN9 results in downregulation of mitotic genes and in upregulation of differentiation-specific genes. ChIP-on chip experiments showed that mitotic genes are direct targets of LIN9 while lineage specific markers are regulated indirectly. Importantly, depletion of LIN9 does not alter the expression of pluripotency markers SOX2, OCT4 and Nanog and LIN9 depleted ESCs retain alkaline phosphatase activity. We conclude that LIN9 is essential for proliferation and genome stability of ESCs by activating genes with important functions in mitosis and cytokinesis. KW - cell cycle KW - cell division KW - cell differentation KW - DNA-binding proteins KW - gene expression KW - gene regulation KW - gene targeting KW - microarrays KW - pluripotency Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96922 ER - TY - JOUR A1 - Lehrnbecher, T. A1 - Merz, H. A1 - Sebald, Walter A1 - Poot, M. T1 - Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4 N2 - Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells. KW - Biochemie KW - BrdU-Hoechst KW - cell cycle KW - flow cytometry KW - interleukin 2 KW - interleukin 4 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62491 ER -