Integrated genomic and transcriptional profiling identifies chromosomal loci with altered gene expression in cervical cancer
GENES CHROMOSOMES & CANCER
Authors: Wilting, Saskia M.; de Wilde, Jillian; Meijer, Chris J. L. M.; Berkhof, Johannes; Yi, Yajun; van Wieringen, Wessel N.; Braakhuis, Boudewijn J. M.; Meijer, Gerrit A.; Ylstra, Bauke; Snijders, Peter J. F.; Steenbergen, Renske D. M.
Abstract
For a better understanding of the consequences of recurrent chromosomal alterations in cervical carcinomas, we integrated genome-wide chromosomal and transcriptional profiles of 10 squamous cell carcinomas (SCCs), 5 adenocarcinomas (AdCAs) and 6 normal controls. Previous genomic profiling showed that gains at chromosome arms 1q, 3q, and 20q as well as losses at 8q, 10q, 11q, and 13q were common in cervical carcinomas. Altered regions spanned multiple megabases, and the extent to which expression of genes located there is affected remains unclear. Expression analysis of these previously chromosomally profiled carcinomas yielded 83 genes with significantly differential expression between carcinomas and normal epithelium. Application of differential gene locus mapping (DIGMAP) analysis and the array CGH expression integration tool (ACE-it) identified hotspots within large chromosomal alterations in which gene expression was altered as well. Chromosomal gains of the long arms of chromosome 1, 3, and 20 resulted in increased expression of genes located at 1q32.1-32.2, 3q13.32-23, 3q26.32-27.3, and 20q11.21-13.33, whereas a chromosomal loss of 11q22.3-25 was related to decreased expression of genes located in this region. Overexpression of DTX3L, PIK3R4, ATP2C1, and SLC25A36, all located at 3q21.1-23 and identified by DIGMAP, ACE-it or both, was confirmed in an independent validation sample set consisting of 12 SCCs and 13 normal ectocervical samples. In conclusion, integrated chromosomal and transcriptional profiling identified chromosomal hotspots at 1q, 3q, 11q, and 20q with altered gene expression within large commonly altered chromosomal regions in cervical cancer. (C) 2008 Wiley-Liss, Inc.
DELTEX2 C-terminal domain recognizes and recruits ADP-ribosylated proteins for ubiquitination
SCIENCE ADVANCES
Authors: Ahmed, Syed Feroj; Buetow, Lori; Gabrielsen, Mads; Lilla, Sergio; Chatrin, Chatrin; Sibbet, Gary J.; Zanivan, Sara; Huang, Danny T.
Abstract
Cross-talk between ubiquitination and ADP-ribosylation regulates spatiotemporal recruitment of key players in many signaling pathways. The DELTEX family ubiquitin ligases (DTX1 to DTX4 and DTX3L) are characterized by a RING domain followed by a C-terminal domain (DTC) of hitherto unknown function. Here, we use two label-free mass spectrometry techniques to investigate the interactome and ubiquitinated substrates of human DTX2 and identify a large proportion of proteins associated with the DNA damage repair pathway. We show that DTX2-catalyzed ubiquitination of these interacting proteins requires PARP1/2-mediated ADP-ribosylation and depends on the DTC domain. Using a combination of structural, biochemical, and cell-based techniques, we show that the DTX2 DTC domain harbors an ADP-ribose-binding pocket and recruits poly-ADP-ribose (PAR)-modified proteins for ubiquitination. This PAR-binding property of DTC domain is conserved across the DELTEX family E3s. These findings uncover a new ADP-ribose-binding domain that facilitates PAR-dependent ubiquitination.