Recent CIG publications Archive

Cell Death Differ. 2011 Jun;18(6):1036-45. Epub 2011 Mar 18.

Logette E, Schuepbach-Mallepell S, Eckert MJ, Leo XH, Jaccard B, Manzl C, Tardivel A, Villunger A, Quadroni M, Gaide O, Tschopp J.

Source

Department of Biochemistry, University of Lausanne, Epalinges, Switzerland.

Abstract

PIDD has been implicated in survival and apoptotic pathways in response to DNA damage, and a role for PIDD was recently identified in non-homologous end-joining (NHEJ) repair induced by γ-irradiation. Here, we present an interaction of PIDD with PCNA, first identified in a proteomics screen. PCNA has essential functions in DNA replication and repair following UV irradiation. Translesion synthesis (TLS) is a process that prevents UV irradiation-induced replication blockage and is characterized by PCNA monoubiquitination and interaction with the TLS polymerase eta (polη). Both of these processes are inhibited by p21. We report that PIDD modulates p21-PCNA dissociation, and promotes PCNA monoubiquitination and interaction with polη in response to UV irradiation. Furthermore, PIDD deficiency leads to a defect in TLS that is associated, both in vitro and in vivo, with cellular sensitization to UV-induced apoptosis. Thus, PIDD performs key functions upon UV irradiation, including TLS, NHEJ, NF-κB activation and cell death.

PMID:21415862[PubMed - indexed for MEDLINE]

PMCID: PMC3131944[Available on 2012/6/1]

PLoS One. 2012;7(1):e28213. Epub 2012 Jan 4.

Djebali S, Lagarde J, Kapranov P, Lacroix V, Borel C, Mudge JM, Howald C, Foissac S, Ucla C, Chrast J, Ribeca P, Martin D, Murray RR, Yang X, Ghamsari L, Lin C, Bell I, Dumais E, Drenkow J, Tress ML, Gelpí JL, Orozco M, Valencia A, van Berkum NL, Lajoie BR, Vidal M, Stamatoyannopoulos J, Batut P, Dobin A, Harrow J, Hubbard T, Dekker J, Frankish A, Salehi-Ashtiani K, Reymond A, Antonarakis SE, Guigó R, Gingeras TR.

Source

Bioinformatics and Genomics, Centre for Genomic Regulation and Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.

Abstract

The classic organization of a gene structure has followed the Jacob and Monod bacterial gene model proposed more than 50 years ago. Since then, empirical determinations of the complexity of the transcriptomes found in yeast to human has blurred the definition and physical boundaries of genes. Using multiple analysis approaches we have characterized individual gene boundaries mapping on human chromosomes 21 and 22. Analyses of the locations of the 5′ and 3′ transcriptional termini of 492 protein coding genes revealed that for 85% of these genes the boundaries extend beyond the current annotated termini, most often connecting with exons of transcripts from other well annotated genes. The biological and evolutionary importance of these chimeric transcripts is underscored by (1) the non-random interconnections of genes involved, (2) the greater phylogenetic depth of the genes involved in many chimeric interactions, (3) the coordination of the expression of connected genes and (4) the close in vivo and three dimensional proximity of the genomic regions being transcribed and contributing to parts of the chimeric RNAs. The non-random nature of the connection of the genes involved suggest that chimeric transcripts should not be studied in isolation, but together, as an RNA network.

Methods Mol Biol. 2012;838:173-86.

Harewood L, Chaignat E, Reymond A.

Source

The Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.

Abstract

Structural variation, whether it is caused by copy number variants or present in a balanced form, such as reciprocal translocations and inversions, can have a profound and dramatic effect on the expression of genes mapping within and close to the rearrangement, as well as affecting others genome wide. These effects can be caused by altering the copy number of one or more genes or regulatory elements (dosage effect) or from physical disruption of links between regulatory elements and their associated gene or genes, resulting in perturbation of expression. Similarly, large-scale structural variants can result in genome-wide expression changes by altering the positions that chromosomes occupy within the nucleus, potentially disrupting not only local cis interactions, but also trans interactions that occur throughout the genome. Structural variation is, therefore, a significant factor in the study of gene expression and is discussed here in more detail.