We describe a novel mammalian DNA binding activity that requires at least two symmetrically methylated CpG dinucleotides in its recognition sequence, preferably within the sequence 5CGCG. A key component of the activity is Kaiso, a protein with POZ and zincfinger domains that is known to associate with p120 catenin. We find that Kaiso behaves as a methylationdependent transcriptional repressor in transient transfection assays. Kaiso is a constituent of one of two methylCpG binding complexes originally designated as MeCP1. The data suggest that zinc-finger motifs are responsible for DNA binding, and may therefore target repression to specific methylated regions of the genome. As Kaiso associates with p120 catenin, Kaiso may link events at the cell surface with DNA methylation-dependent gene silencing.

In vertebrates, densely methylated DNA is associated with inactive transcription. Actors in this process include proteins of the MBD family that can recognize methylated CpGs and repress transcription. Kaiso, a structurally unrelated protein, has also been shown to bind methylated CGCGs through its three Krüppel-like C 2 H 2 zinc fingers. The human genome contains two uncharacterized proteins, ZBTB4 and ZBTB38, that contain Kaiso-like zinc fingers. We report that ZBTB4 and ZBTB38 bind methylated DNA in vitro and in vivo. Unlike Kaiso, they can bind single methylated CpGs. When transfected in mouse cells, the proteins colocalize with foci of heavily methylated satellite DNA and become delocalized upon loss of DNA methylation. Chromatin immunoprecipitation suggests that both of these proteins specifically bind to the methylated allele of the H19/Igf2 differentially methylated region. ZBTB4 and ZBTB38 repress the transcription of methylated templates in transfection assays. The two genes have distinct tissue-specific expression patterns, but both are highly expressed in the brain. Our results reveal the existence of a family of Kaiso-like proteins that bind methylated CpGs. Like proteins of the MBD family, they are able to repress transcription in a methyl-dependent manner, yet their tissue-specific expression pattern suggests nonoverlapping functions.

contributed to the design and execution of the overall study. M.P.P., M.J., J.R.T., G.S., L.E.M., L.A.K., X.W., V.G., K.B.J., J.D.M., N.R., S.J.C., and P Brennan contributed to the statistical analysis. M.P.P., M.J., S.J.C. and P. Brennan wrote the first draft of the manuscript. D. Zeleniak, E.P., L.A.K., X.W., K.B.J., S.H.V., S.L.M., Y.Y., A.M.M., E.S.B., N.N.C., M.F., D.L., I.G., S.H., H. Blanche, A.H., G.T., Z.W., M.Y., K.G.S., S.J.C., and M.L. supervised or conducted the genotyping. The remaining authors conducted the epidemiologic studies and contributed samples to the GWAS and/or replication. All authors contributed to the writing of the manuscript. NIH Public Access Author ManuscriptNat Genet. Author manuscript; available in PMC 2012 January 1. AbstractWe conducted a two-stage genome-wide association study of renal cell carcinoma (RCC) in 3,772 cases and 8,505 controls of European background from 11 studies, and followed up 6 SNPs in three replication studies of 2,198 cases and 4,918 controls. Two loci on the regions of 2p21 and 11q13.3 were associated with RCC susceptibility below genome-wide significance. Two correlated variants (r 2 = 0.99 in controls), rs11894252 (P = 1.8×10 −8 ) and rs7579899 (P = 2.3×10 −9 ), map to EPAS1 on 2p21, which encodes hypoxia-inducible-factor-2 alpha, a transcription factor previously implicated in RCC. The second locus, rs7105934, at 11q13, contains no characterized genes (P = 7.8×10 −14 ). In addition, we observed a promising association on 12q24.31 for rs4765623 which maps to the scavenger receptor class B, member 1 (SCARB1) gene (P = 2.6×10 −8 ). Our study reports novel genomic regions associated with RCC risk that may lead to new etiological insights. Table 1, Online Methods and Supplementary note). All subjects from the IARC/CNG study were genotyped at the CNG with the exception of 305 cases and 323 controls from Russia that were genotyped at the Center "Bioengineering" and at the "Kurchatov Institute" in Moscow. All subjects from the NCI study were scanned at the NCI Core Genotyping Facility. In addition, 1,438 controls from the Wellcome Trust Case-Control Consortium were genotyped at the Sanger Institute, UK 10 . All RCC cases were defined on the basis of the International Classification of Diseases for Oncology, Second Edition (ICD-O-2), and included all cancers that were coded as C64.Comparable quality control metrics were applied to the two scanned data sets and following sample and SNP exclusions, genotype data for up to 577,547 SNPs were available for 2,461 cases and 5,081 controls in the IARC/CNG scan, while data for 585,576 SNPs were available for 1,311 cases and 3,424 controls in the NCI scan (Online Methods). Primary analyses were conducted using unconditional logistic regression models for genotype trend effects (1 degree of freedom) and adjusted for sex, country, eigenvectors, and study for the USA (Online Methods). In order to compute summary findings across both scans, a metaanalysis was performed using a fixed effects model with inverse variance wei...

Epigenetic information is available from contemporary organisms, but is difficult to track back in evolutionary time. Here, we show that genome-wide epigenetic information can be gathered directly from next-generation sequence reads of DNA isolated from ancient remains. Using the genome sequence data generated from hair shafts of a 4000-yr-old Paleo-Eskimo belonging to the Saqqaq culture, we generate the first ancient nucleosome map coupled with a genome-wide survey of cytosine methylation levels. The validity of both nucleosome map and methylation levels were confirmed by the recovery of the expected signals at promoter regions, exon/intron boundaries, and CTCF sites. The top-scoring nucleosome calls revealed distinct DNA positioning biases, attesting to nucleotide-level accuracy. The ancient methylation levels exhibited high conservation over time, clustering closely with modern hair tissues. Using ancient methylation information, we estimated the age at death of the Saqqaq individual and illustrate how epigenetic information can be used to infer ancient gene expression. Similar epigenetic signatures were found in other fossil material, such as 110,000- to 130,000-yr-old bones, supporting the contention that ancient epigenomic information can be reconstructed from a deep past. Our findings lay the foundation for extracting epigenomic information from ancient samples, allowing shifts in epialleles to be tracked through evolutionary time, as well as providing an original window into modern epigenomics.