Rainer Pepperkok

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DNA double-strand breaks (DSBs) not only interrupt the genetic information, but also disrupt the chromatin structure, and both impairments require repair mechanisms to ensure genome integrity. We showed previously that RNF8-mediated chromatin ubiquitylation protects genome integrity by promoting the accumulation of repair factors at DSBs. Here, we provide(More)
Exocytic transport from the endoplasmic reticulum (ER) to the Golgi complex has been visualized in living cells using a chimera of the temperature-sensitive glycoprotein of vesicular stomatitis virus and green fluorescent protein (ts-G-GFP[ct]). Upon shifting to permissive temperature, ts-G-GFP(ct) concentrates into COPII-positive structures close to the(More)
Microinjection of antibodies against a synthetic peptide of a non-clathrin-coated vesicle-associated coat protein, beta-COP, blocks transport of a temperature-sensitive vesicular stomatitis virus glycoprotein (ts-O45-G) to the cell surface. Transport is inhibited upon release of the viral glycoprotein from temperature blocks at 39.5 degrees C (endoplasmic(More)
We have recently shown that discrete foci are present in the nuclei of mammalian cells in which each of the U1, U2, U4/U6, and U5 snRNPs involved in pre-mRNA splicing, and the non-snRNP-splicing factor U2AF, are concentrated (Carmo-Fonseca, M., D. Tollervey, R. Pepperkok, S. Barabino, A. Merdes, C. Brunner, P. D. Zamore, M. R. Green, E. Hurt, and A. I.(More)
Cyclins play a fundamental role in regulating cell cycle events in all eukaryotic cells. The human cyclin A gene was identified as the site of integration of hepatitis B virus in a hepatocarcinoma cell line; in addition, cyclin A is associated with the E2F transcription factor in a complex which is dissociated by the E1A oncogene product. Such findings(More)
Despite our rapidly growing knowledge about the human genome, we do not know all of the genes required for some of the most basic functions of life. To start to fill this gap we developed a high-throughput phenotypic screening platform combining potent gene silencing by RNA interference, time-lapse microscopy and computational image processing. We carried(More)
In Xenopus laevis egg extracts, TPX2 is required for the Ran-GTP-dependent assembly of microtubules around chromosomes. Here we show that interfering with the function of the human homologue of TPX2 in HeLa cells causes defects in microtubule organization during mitosis. Suppressing the expression of human TPX2 by RNA interference leads to the formation of(More)
Hepatitis C virus (HCV) is a major causative agent of chronic liver disease in humans. To gain insight into host factor requirements for HCV replication, we performed a siRNA screen of the human kinome and identified 13 different kinases, including phosphatidylinositol-4 kinase III alpha (PI4KIIIα), as being required for HCV replication. Consistent with(More)
During mitosis, the ribbon of the Golgi apparatus is transformed into dispersed tubulo-vesicular membranes, proposed to facilitate stochastic inheritance of this low copy number organelle at cytokinesis. Here, we have analyzed the mitotic disassembly of the Golgi apparatus in living cells and provide evidence that inheritance is accomplished through an(More)
TPX2 has multiple functions during mitosis, including microtubule nucleation around the chromosomes and the targeting of Xklp2 and Aurora A to the spindle. We have performed a detailed domain functional analysis of TPX2 and found that a large N-terminal domain containing the Aurora A binding peptide interacts directly with and nucleates microtubules in pure(More)