Rif1 S-acylation mediates DNA double-strand break repair at the inner nuclear membrane

Rif1 is involved in telomere homeostasis, DNA replication timing, and DNA double-strand break (DSB) repair pathway choice from yeast to human. The molecular mechanisms that enable Rif1 to fulfill its diverse roles remain to be determined. Here, we demonstrate that Rif1 is S-acylated within its conserved N-terminal domain at cysteine residues C466 and C473 by the DHHC family palmitoyl acyltransferase Pfa4. Rif1 S-acylation facilitates the accumulation of Rif1 at DSBs, the attenuation of DNA end-resection, and DSB repair by non-homologous end-joining (NHEJ). These findings identify S-acylation as a posttranslational modification regulating DNA repair. S-acylated Rif1 mounts a localized DNA-damage response proximal to the inner nuclear membrane, revealing a mechanism of compartmentalized DSB repair pathway choice by sequestration of a fatty acylated repair factor at the inner nuclear membrane

A hard nut to crack : regulatory failure shows how rating really works

Credit rating agencies such as Moody’s and Standard & Poor’s are key players in the governance of global financial markets. Given the very strong criticism the rating agencies faced in the wake of the global financial crisis 2008, how can we explain the puzzle of their survival? Market and regulatory reliance on ratings continues, despite the shift from a light-touch to a mandatory system of agency regulation and supervision. Drawing on the analysis of rating agency regulation in the US and the EU before and after the financial crisis, we argue that a pervasive, persistent and, in our view, erroneous understanding of rating has supported the never-ending story of rating agency authority. We show how treating ratings as metrics, private goods, and independent and neutral third-party opinions contributes to the ineffectiveness of rating agency regulation and supports the continuing authoritative standing of the credit rating agencies in market and regulatory practices

Rif1 maintains telomeres and mediates DNA repair by encasing DNA ends

In yeast, Rif1 is part of the telosome, where it inhibits telomerase and checkpoint signaling at chromosome ends. In mammalian cells, Rif1 is not telomeric, but it suppresses DNA end resection at chromosomal breaks, promoting repair by nonhomologous end joining (NHEJ). Here, we describe crystal structures for the uncharacterized and conserved ∼125-kDa N-terminal domain of Rif1 from Saccharomyces cerevisiae (Rif1-NTD), revealing an α-helical fold shaped like a shepherd's crook. We identify a high-affinity DNA-binding site in the Rif1-NTD that fully encases DNA as a head-to-tail dimer. Engagement of the Rif1-NTD with telomeres proved essential for checkpoint control and telomere length regulation. Unexpectedly, Rif1-NTD also promoted NHEJ at DNA breaks in yeast, revealing a conserved role of Rif1 in DNA repair. We propose that tight associations between the Rif1-NTD and DNA gate access of processing factors to DNA ends, enabling Rif1 to mediate diverse telomere maintenance and DNA repair functions

The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε

Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding abilit

Effects of assessing the productivity of faculty in academic medical centres : a systematic review

Background: Many academic medical centres have introduced strategies to assess the productivity of faculty as part of compensation schemes. We conducted a systematic review of the effects of such strategies on faculty productivity. Methods: We searched the MEDLINE, Healthstar, Embase and PsycInfo databases from their date of inception up to October 2011. We included studies that assessed academic productivity in clinical, research, teaching and administrative activities, as well as compensation, promotion processes and satisfaction. Results: Of 531 full-text articles assessed for eligibility, we in cluded 9 articles reporting on eight studies. The introduction of strategies for assessing academic productivity as part of compensation schemes resulted in increases in clinical productivity (in six of six studies) in terms of clinical revenue, the work component of relative-value units (these units are nonmonetary standard units of measure used to indicate the value of services provided), patient satisfaction and other departmentally used standards. Increases in research productivity were noted (in five of six studies) in terms of funding and publications. There was no change in teaching productivity (in two of five studies) in terms of educational output. Such strategies also resulted in increases in compensation at both individual and group levels (in three studies), with two studies re - porting a change in distribution of compensation in favour of junior faculty. None of the studies assessed effects on administrative productivity or promotion processes. The overall quality of evidence was low. Interpretation: Strategies introduced to assess productivity as part of a compensation scheme appeared to improve productivity in research activities and possibly improved clinical productivity, but they had no effect in the area of teaching. Compensation increased at both group and individual levels, particularly among junior faculty. Higher quality evidence about the benefits and harms of such assessment strategies is needed

Intracellular insulin in human tumors: examples and implications

Insulin is one of the major metabolic hormones regulating glucose homeostasis in the organism and a key growth factor for normal and neoplastic cells. Work conducted primarily over the past 3 decades has unravelled the presence of insulin in human breast cancer tissues and, more recently, in human non-small cell lung carcinomas (NSCLC). These findings have suggested that intracellular insulin is involved in the development of these highly prevalent human tumors. A potential mechanism for such involvement is insulin's binding and inactivation of the retinoblastoma tumor suppressor protein (RB) which in turn is likely controlled by insulin-degrading enzyme (IDE). This model and its supporting data are collectively covered in this survey in order to provide further insight into insulin-driven oncogenesis and its reversal through future anticancer therapeutics

Human Papillomavirus-16 E7 Interacts with Glutathione S-Transferase P1 and Enhances Its Role in Cell Survival

Background:Human Papillomavirus (HPV)-16 is a paradigm for "high-risk" HPVs, the causative agents of virtually all cervical carcinomas. HPV E6 and E7 viral genes are usually expressed in these tumors, suggesting key roles for their gene products, the E6 and E7 oncoproteins, in inducing malignant transformation.Methodology/Principal Findings:By protein-protein interaction analysis, using mass spectrometry, we identified glutathione S-transferase P1-1 (GSTP1) as a novel cellular partner of the HPV-16 E7 oncoprotein. Following mapping of the region in the HPV-16 E7 sequence that is involved in the interaction, we generated a three-dimensional molecular model of the complex between HPV-16 E7 and GSTP1, and used this to engineer a mutant molecule of HPV-16 E7 with strongly reduced affinity for GSTP1.When expressed in HaCaT human keratinocytes, HPV-16 E7 modified the equilibrium between the oxidized and reduced forms of GSTP1, thereby inhibiting JNK phosphorylation and its ability to induce apoptosis. Using GSTP1-deficient MCF-7 cancer cells and siRNA interference targeting GSTP1 in HaCaT keratinocytes expressing either wild-type or mutant HPV-16 E7, we uncovered a pivotal role for GSTP1 in the pro-survival program elicited by its binding with HPV-16 E7.Conclusions/Significance:This study provides further evidence of the transforming abilities of this oncoprotein, setting the groundwork for devising unique molecular tools that can both interfere with the interaction between HPV-16 E7 and GSTP1 and minimize the survival of HPV-16 E7-expressing cancer cells. © 2009 Mileo et al

Mouse Rif1 is a regulatory subunit of protein phosphatase 1 (PP1)

International audienceRif1 is a conserved protein that plays essential roles in orchestrating DNA replication timing, controlling nuclear architecture, telomere length and DNA repair. However, the relationship between these different roles, as well as the molecular basis of Rif1 function is still unclear. The association of Rif1 with insoluble nuclear lamina has thus far hampered exhaustive characterization of the associated protein complexes. We devised a protocol that overcomes this problem, and were thus able to discover a number of novel Rif1 interactors, involved in chromatin metabolism and phosphorylation. Among them, we focus here on PP1. Data from different systems have suggested that Rif1-PP1 interaction is conserved and has important biological roles. Using mutagenesis, NMR, isothermal calorimetry and surface plasmon resonance we demonstrate that Rif1 is a high-affinity PP1 adaptor, able to out-compete the well-established PP1-inhibitor I2 in vitro. Our conclusions have important implications for understanding Rif1 diverse roles and the relationship between the biological processes controlled by Rif1

Proptech, le nuove strade del mercato immobiliare

Il mercato immobiliare negli ultimi anni ha subito profondi cambiamenti legati ai cambiamenti della domanda e dell’offerta guidati dall’utilizzo della nuova tecnologia per l’offerta di servizi alla clientela. Le innovazioni hanno interessato la fase di negoziazione, la fase di gestione degli immobili (in locazione o di proprietà) e la fase di finanziamento delle operazioni di investimento immobiliare, per le opportunità derivanti, tra l’altro, in termini di aumento del numero di clienti, razionalizzazione dei costi e creazione di nuovi canali di raccolta di capitali. Il mercato mondiale del proptech vede una forte presenza di operatori domiciliati in America e in Europa, mentre il mercato italiano è in evoluzione con imprese prevalentemente nate dopo il 2010

Linee metropolitane e interventi di sviluppo e rigenerazione. Milano

The office market has undergone to radical changes in recent years. The working standard adopted by corporations has been changed, moving from one-room offices to open-space and now flexible and adaptable offices according to employees’ needs. Therefore, the supply of offices had to adapt to this new demand and developers tried to create a new type of office through both new projects and renovations of existing buildings. In the last years, even before the Covid-19 pandemic, the city of Milan has seen a process of renewal of the office stock. This process started with an urban regeneration activity that bring to the realization of the Porta Nuova project, that replaced the “Varesine”, and of CityLife, in the area of the former fair. These new developments then led to a restructuring process on other existing buildings in the city, mainly in the historic centre (around Piazza Duomo and Piazza Cordusio) and around Corso Como. By analysing the developments in the city of Milan, it is clear that the new projects, both under construction and still in the planning phase, mainly develop along the metro lines and, with the arrival of Covid-19, attention paid to the use of public transport public to come to the office has even increased. The paper aims to analyse the Milan office market and highlight the role of the metro service on the start-up of development and real estate regeneration sites. The analysis will examine the pipeline of new of real estate projects in the Milan area, highlighting the potential impact also on other types of properties and more generally on the community. Results represent a complete analysis of the main Italian office market but can give interesting insights for the evaluation of interventions also in other cities of the country that are attractive for corporate investment, such as Rome