A novel ubiquitin mark at the N-terminal tail of histone H2As targeted by RNF168 ubiquitin ligase

Ubiquitination of histones plays a critical role in the regulation of several processes within the nucleus, including maintenance of genome stability and transcriptional regulation. The only known ubiquitination site on histones is represented by a conserved Lys residue located at the C terminus of the protein. Here, we describe a novel ubiquitin mark at the N-terminal tail of histone H2As consisting of two Lys residues at positions 13 and 15 (K13/K15). This "bidentate" site is a target of the DNA damage response (DDR) ubiquitin ligases RNF8 and RNF168. Histone mutants lacking the K13/K15 site impair RNF168- and DNA damage-dependent ubiquitination. Conversely, inactivation of the canonical C-terminal site prevents the constitutive monoubiquitination of histone H2As but does not abolish the ubiquitination induced by RNF168. A ubiquitination-defective mutant is obtained by inactivating both the N- and the C-terminal sites, suggesting that these are unique, non-redundant acceptors of ubiquitination on histone H2As. This unprecedented result implies that RNF168 generates a qualitatively different Ub mark on chromatin

Pre and Post Liver Lesion Thermal ablation FDG-PET: background driven GMM segmentation

Two novel and innovative segmentation algorithms are presented, for liver metastases and necrotic tissues in pre- and post-ablation, respectively. Both are based on Gaussian Mixture Model (GMM), adapted to include healthy liver knowledge and proximity information. Preliminary validation results on 20 patients and 42 lesions are discussed showing high accuracy versus manual segmentation gold standard outperforming simpler GMM and thresholding methods

Profilazione e pubblicità comportamentale

Balboni, P. (2013) Profilazione e pubblicità comportamentale. In N. Bernardi, M. Perego, M. Polacchini & M. Soffientini (eds.), Privacy Officer. La figura chiave della data protection europea, IPSOA, Milan, 148 – 15