MCM double hexamer loading visualized with human proteins.

Eukaryotic DNA replication begins with the loading of the MCM replicative DNA helicase as a head-to-head double hexamer at origins of DNA replication. Our current understanding of how the double hexamer is assembled by the origin recognition complex (ORC), CDC6 and CDT1 comes mostly from budding yeast. Here we characterize human double hexamer (hDH) loading using biochemical reconstitution and cryo-electron microscopy with purified proteins.

Loss of MGA repression mediated by an atypical polycomb complex promotes tumor progression and invasiveness.

MGA, a transcription factor and member of the MYC network, is mutated or deleted in a broad spectrum of malignancies. As a critical test of a tumor suppressive role, we inactivated in two mouse models of non-small cell lung cancer using a CRISPR-based approach. MGA loss significantly accelerated tumor growth in both models and led to de-repression of non-canonical Polycomb ncPRC1.

Protein neddylation as a therapeutic target in pulmonary and extrapulmonary small cell carcinomas.

Small cell lung carcinoma (SCLC) is among the most lethal of all solid tumor malignancies. In an effort to identify novel therapeutic approaches for this recalcitrant cancer type, we applied genome-scale CRISPR/Cas9 inactivation screens to cell lines that we derived from a murine model of SCLC. SCLC cells were particularly sensitive to the deletion of NEDD8 and other neddylation pathway genes.

Comparison of HIV Viral Suppression Between a Sample of Foreign-Born and U.S.-Born Women of Color in the United States.

Unlabelled: We investigate the association between nativity status (U.S.- vs foreignborn) and viral suppression among women of color (WOC) with HIV (HIV +) and whether this association was modified by education and housing.

Co-occupancy identifies transcription factor co-operation for axon growth.

Transcription factors (TFs) act as powerful levers to regulate neural physiology and can be targeted to improve cellular responses to injury or disease. Because TFs often depend on cooperative activity, a major challenge is to identify and deploy optimal sets. Here we developed a bioinformatics pipeline, centered on TF co-occupancy of regulatory DNA, and used it to predict factors that potentiate the effects of pro-regenerative Klf6 in vitro.

Dimerisation of the PICTS complex via LC8/Cut-up drives co-transcriptional transposon silencing in .

In animal gonads, the PIWI-interacting RNA (piRNA) pathway guards genome integrity in part through the co-transcriptional gene silencing of transposon insertions. In ovaries, piRNA-loaded Piwi detects nascent transposon transcripts and instructs heterochromatin formation through the anoramix-nduced o-ranscriptional ilencing (PICTS) complex, containing Panoramix, Nxf2 and Nxt1. Here, we report that the highly conserved dynein light chain LC8/Cut-up (Ctp) is an essential component of the PICTS complex.

drives chemoresistance in small cell lung cancer while USP7 inhibition can restore chemosensitivity.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine cancer characterized by initial chemosensitivity followed by emergence of chemoresistant disease. To study roles for amplification in SCLC progression and chemoresistance, we developed a genetically engineered mouse model of -overexpressing SCLC. In treatment-naïve mice, overexpression promoted cell cycle progression, suppressed infiltration of cytotoxic T cells, and accelerated SCLC.

Young Transgender Women of Color: Homelessness, Poverty, Childhood Sexual Abuse and Implications for HIV Care.

This study describes a sample of HIV+ young transgender women of color aged 18-24 and their experience with homelessness as part of a demonstration project of engagement and retention in HIV medical care funded by Health Resources and Services Administration. The study engaged transgender women of color in HIV care in nine sites across the US between 2012 and 2017. This analysis describes and compares transwomen who had been homeless in the last 6 months to those not homeless.

Specialization of the nuclear export family protein Nxf3 for piRNA precursor export.

The PIWI-interacting RNA (piRNA) pathway is a conserved small RNA-based immune system that protects animal germ cell genomes from the harmful effects of transposon mobilization. In ovaries, most piRNAs originate from dual-strand clusters, which generate piRNAs from both genomic strands. Dual-strand clusters use noncanonical transcription mechanisms.

piRNA-guided co-transcriptional silencing coopts nuclear export factors.

The PIWI-interacting RNA (piRNA) pathway is a small RNA-based immune system that controls the expression of transposons and maintains genome integrity in animal gonads. In , piRNA-guided silencing is achieved, in part, via co-transcriptional repression of transposons by Piwi. This depends on Panoramix (Panx); however, precisely how an RNA binding event silences transcription remains to be determined.

Daedalus and Gasz recruit Armitage to mitochondria, bringing piRNA precursors to the biogenesis machinery.

The Piwi-interacting RNA (piRNA) pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. piRNA biogenesis requires a specialized machinery that converts long single-stranded precursors into small RNAs of ∼25-nucleotides in length. This process involves factors that operate in two different subcellular compartments: the nuage/Yb body and mitochondria.

Targeting NOTCH activation in small cell lung cancer through LSD1 inhibition.

Small cell lung cancer (SCLC) is a recalcitrant, aggressive neuroendocrine-type cancer for which little change to first-line standard-of-care treatment has occurred within the last few decades. Unlike nonsmall cell lung cancer (NSCLC), SCLC harbors few actionable mutations for therapeutic intervention. Lysine-specific histone demethylase 1A (LSD1 also known as KDM1A) inhibitors were previously shown to have selective activity in SCLC models, but the underlying mechanism was elusive.

piRNA-Guided Genome Defense: From Biogenesis to Silencing.

PIWI-interacting RNAs (piRNAs) and their associated PIWI clade Argonaute proteins constitute the core of the piRNA pathway. In gonadal cells, this conserved pathway is crucial for genome defense, and its main function is to silence transposable elements. This is achieved through posttranscriptional and transcriptional gene silencing.

Loss Drives Small Cell Lung Cancer and Increases Sensitivity to HDAC Inhibition.

, encoding an acetyltransferase, is among the most frequently mutated genes in small cell lung cancer (SCLC), a deadly neuroendocrine tumor type. We report acceleration of SCLC upon inactivation in an autochthonous mouse model. Extending these observations beyond the lung, broad deletion in mouse neuroendocrine cells cooperated with loss to promote neuroendocrine thyroid and pituitary carcinomas.

KLF6 and STAT3 co-occupy regulatory DNA and functionally synergize to promote axon growth in CNS neurons.

The failure of axon regeneration in the CNS limits recovery from damage and disease. Members of the KLF family of transcription factors can exert both positive and negative effects on axon regeneration, but the underlying mechanisms are unclear. Here we show that forced expression of KLF6 promotes axon regeneration by corticospinal tract neurons in the injured spinal cord.

Verification of a genetic locus for methamphetamine intake and the impact of morphine.

A quantitative trait locus (QTL) on proximal chromosome (Chr) 10 accounts for > 50% of the genetic variance in methamphetamine (MA) intake in mice selectively bred for high (MAHDR) and low (MALDR) voluntary MA drinking. The µ-opioid receptor (MOP-r) gene, Oprm1, resides at the proximal end of Chr 10, and buprenorphine reduces MA intake in MAHDR mice. However, this drug has only partial agonist effects at MOP-r.

Inclusion Body Myositis: What Most Impacts Patients' Lives.

Objective: Inclusion body myositis (IBM) is the most common form of idiopathic inflammatory myopathy in adults older than 50 years. Few studies have focused on the functional, physical, and social limitations of this disease. This study identifies pertinent symptoms that impact the health and daily function of patients with IBM.

Population Connectivity Measures of Fishery-Targeted Coral Reef Species to Inform Marine Reserve Network Design in Fiji.

Coral reef fish serve as food sources to coastal communities worldwide, yet are vulnerable to mounting anthropogenic pressures like overfishing and climate change. Marine reserve networks have become important tools for mitigating these pressures, and one of the most critical factors in determining their spatial design is the degree of connectivity among different populations of species prioritized for protection. To help inform the spatial design of an expanded reserve network in Fiji, we used rapidly evolving mitochondrial genes to investigate connectivity patterns of three coral reef species targeted by fisheries in Fiji: Epinephelus merra (Serranidae), Halichoeres trimaculatus (Labridae), and Holothuria atra (Holothuriidae).

Health status of HIV-infected women entering care: baseline medical findings from the women of color initiative.

The WOC Initiative is a prospective study of 921 women of color (WOC) entering HIV care at nine (three rural, six urban) sites across the US. A baseline interview was performed that included self-reported limitation(s) in activity, health conditions, and the CDC's health-related quality of life measures (Healthy Days). One-third of the WOC reported limiting an activity because of illness or a health condition and those with an activity limitation reported 13 physically and 14 mentally unhealthy days/month, compared with 5 physically and 9 mentally unhealthy days/month in the absence of an activity limitation.

Baseline social characteristics and barriers to care from a special projects of national significance women of color with HIV study: a comparison of urban and rural women and barriers to HIV care.

We describe the baseline sociodemographic characteristics of the Health Resources and Services Administration's Special Programs of National Significance Women of Color (WOC) Initiative. Between November 2010 and July 2013, 921 WOC were prospectively enrolled in HIV medical care at nine sites, six urban (N = 641) and three rural sites (N = 280) across the US. We describe the study sample, drawing comparisons between urban and rural sites on sociodemographics, barriers to HIV care, HIV care status at study entry, substance use and sexual risk factors, and the relationship among these variables.

Barriers and facilitators to the implementation of SPNS interventions designed to engage and retain HIV positive women of color in medical care.

The use of evidence-based strategies to increase access to medical care and improve health outcomes for people living with HIV is a major public health priority in the United States. As part of a multi-site evaluation funded under the Health Resources and Services Administration (HRSA), a process evaluation was conducted with the goal of understanding barriers and facilitators to the implementation of eleven heterogeneous interventions designed to engage and retain HIV positive women of color (WoC) in medical care. Findings identified barriers and facilitators to program implementation at five levels: (1) program; (2) team; (3) agency; (4) partner network; and (5) the larger socio-ecological context.

Methamphetamine drinking microstructure in mice bred to drink high or low amounts of methamphetamine.

Genetic factors likely influence individual sensitivity to positive and negative effects of methamphetamine (MA) and risk for MA dependence. Genetic influence on MA consumption has been confirmed by selectively breeding mouse lines to consume high (MAHDR) or low (MALDR) amounts of MA, using a two-bottle choice MA drinking (MADR) procedure. Here, we employed a lickometer system to characterize the microstructure of MA (20, 40, and 80mg/l) and water intake in MAHDR and MALDR mice in 4-h limited access sessions, during the initial 4hours of the dark phase of their 12:12h light:dark cycle.

Morphine intake and the effects of naltrexone and buprenorphine on the acquisition of methamphetamine intake.

Some common genetic factors appear to influence risk for drug dependence across multiple drugs of abuse. In previous research, mice that were selectively bred for higher amounts of methamphetamine consumption, using a two-bottle choice methamphetamine drinking procedure, were found to be less sensitive to the locomotor stimulant effects of morphine and of the more selective μ-opioid receptor agonist fentanyl, compared to mice that were bred for low methamphetamine consumption. This suggested that μ-opioid receptor-mediated pathways may influence genetic risk for methamphetamine consumption.

The impact of congenital and childhood myotonic dystrophy on quality of life: a qualitative study of associated symptoms.

This study systematically evaluated the symptoms associated with congenital and childhood myotonic dystrophy, and how these symptoms affect health related quality of life. We conducted interviews with patients affected by congenital or childhood myotonic dystrophy and their affected parent to identify which symptoms have the greatest effect on their lives. Each interview was recorded, coded, and analyzed using a qualitative framework technique.