Human cytomegalovirus mediates APOBEC3B relocalization early during infection through a ribonucleotide reductase-independent mechanism

Human cytomegalovirus (HCMV) infections can range from asymptomatic to severe, particularly in neonates and immunocompromised patients. HCMV has evolved strategies to overcome host-encoded antiviral defenses to achieve lytic viral DNA replication and dissemination and, under some conditions, latency and long-term persistence. Here, we show that HCMV infection causes the antiviral factor, APOBEC3B, to relocalize from the nuclear compartment to the cytoplasm. This overall strategy resembles that used by related herpesviruses. However, the HCMV relocalization mechanism utilizes a different viral factor(s) and available evidence suggests the involvement of at least one protein expressed at the early stages of infection. This knowledge is important because a greater understanding of this mechanism could lead to novel antiviral strategies that enable APOBEC3B to naturally restrict HCMV infection.The APOBEC3 family of DNA cytosine deaminases comprises an important arm of the innate antiviral defense system. The gamma-herpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus and the alpha-herpesviruses herpes simplex virus (HSV)-1 and HSV-2 have evolved an efficient mechanism to avoid APOBEC3 restriction by directly binding to APOBEC3B and facilitating its exclusion from the nuclear compartment. The only viral protein required for APOBEC3B relocalization is the large subunit of the ribonucleotide reductase (RNR). Here, we ask whether this APOBEC3B relocalization mechanism is conserved with the beta-herpesvirus human cytomegalovirus (HCMV). Although HCMV infection causes APOBEC3B relocalization from the nucleus to the cytoplasm in multiple cell types, the viral RNR (UL45) is not required. APOBEC3B relocalization occurs rapidly following infection suggesting the involvement of an immediate early or early (IE/E) viral protein. In support of this possibility, genetic (IE1 mutant) and pharmacologic (cycloheximide) strategies that prevent the expression of IE/E viral proteins also block APOBEC3B relocalization. In comparison, the treatment of infected cells with phosphonoacetic acid, which interferes with viral late protein expression, still permits A3B relocalization. These results combine to indicate that the beta-herpesvirus HCMV uses an RNR-independent, yet phenotypically similar, molecular mechanism to antagonize APOBEC3B. IMPORTANCEHuman cytomegalovirus (HCMV) infections can range from asymptomatic to severe, particularly in neonates and immunocompromised patients. HCMV has evolved strategies to overcome host-encoded antiviral defenses to achieve lytic viral DNA replication and dissemination and, under some conditions, latency and long-term persistence. Here, we show that HCMV infection causes the antiviral factor, APOBEC3B, to relocalize from the nuclear compartment to the cytoplasm. This overall strategy resembles that used by related herpesviruses. However, the HCMV relocalization mechanism utilizes a different viral factor(s) and available evidence suggests the involvement of at least one protein expressed at the early stages of infection. This knowledge is important because a greater understanding of this mechanism could lead to novel antiviral strategies that enable APOBEC3B to naturally restrict HCMV infection

Fourteen Recommendations to Create a More Inclusive Environment for LGBTQ+ Individuals in Academic Biology

Individuals who identify as lesbian, gay, bisexual, transgender, queer, and otherwise non-straight and/or non-cisgender (LGBTQ+) have often not felt welcome or represented in the biology community. Additionally, biology can present unique challenges for LGBTQ+ students because of the relationship between certain biology topics and their LGBTQ+ identities. Currently, there is no centralized set of guidelines to make biology learning environments more inclusive for LGBTQ+ individuals. Rooted in prior literature and the collective expertise of the authors who identify as members and allies of the LGBTQ+ community, we present a set of actionable recommendations to help biologists, biology educators, and biology education researchers be more inclusive of individuals with LGBTQ+ identities. These recommendations are intended to increase awareness of LGBTQ+ identities and spark conversations about transforming biology learning spaces and the broader academic biology community to become more inclusive of LGBTQ+ individuals

APOBEC3B drives PKR-mediated translation shutdown and protects stress granules in response to viral infection

Double-stranded RNA produced during viral replication and transcription activates both protein kinase R (PKR) and ribonuclease L (RNase L), which limits viral gene expression and replication through host shutoff of translation. In this study, we find that APOBEC3B forms a complex with PABPC1 to stimulate PKR and counterbalances the PKR-suppressing activity of ADAR1 in response to infection by many types of viruses. This leads to translational blockage and the formation of stress granules. Furthermore, we show that APOBEC3B localizes to stress granules through the interaction with PABPC1. APOBEC3B facilitates the formation of protein-RNA condensates with stress granule assembly factor (G3BP1) by protecting mRNA associated with stress granules from RNAse L-induced RNA cleavage during viral infection. These results not only reveal that APOBEC3B is a key regulator of different steps of the innate immune response throughout viral infection but also highlight an alternative mechanism by which APOBEC3B can impact virus replication without editing viral genomes

Fourteen Recommendations to Create a More Inclusive Environment for LGBTQ+ Individuals in Academic Biology

Individuals who identify as lesbian, gay, bisexual, transgender, queer, and otherwise nonstraight and/or non-cisgender (LGBTQ+) have often not felt welcome or represented in the biology community. Additionally, biology can present unique challenges for LGBTQ+ students because of the relationship between certain biology topics and their LGBTQ+ identities. Currently, there is no centralized set of guidelines to make biology learning environments more inclusive for LGBTQ+ individuals. Rooted in prior literature and the collective expertise of the authors who identify as members and allies of the LGBTQ+ community, we present a set of actionable recommendations to help biologists, biology educators, and biology education researchers be more inclusive of individuals with LGBTQ+ identities. These recommendations are intended to increase awareness of LGBTQ+ identities and spark conversations about transforming biology learning spaces and the broader academic biology community to become more inclusive of LGBTQ+ individuals

Focusing National Institutes of Health HIV/AIDS Research for Maximum Population Impact

Progress in advancing research on the pathophysiology, prevention, treatment, and impact of human immunodeficiency virus (HIV) is threatened by the decaying purchasing power of National Institutes of Health (NIH) dollars. A working group of the NIH Office of AIDS Research Advisory Council was charged by the NIH Director with developing a focused and concise blueprint to guide the use of limited funding over the next few years. Science priorities outlined by the working group and reported here are intended to maximally address individuals, groups, and settings most affected by the epidemic, and to redress shortcomings in realizing population-level HIV prevention, treatment, and eradication goals. Optimizing these priorities requires that traditional silos—defined by topic focus and by scientific discipline—be dissolved and that structural issues affecting the pipeline of new investigators and the ability of the Office of AIDS Research to fulfill its role of steward of the NIH HIV/AIDS research program be directly addressed

Factors Associated With Improved Pediatric Resuscitative Care in General Emergency Departments

OBJECTIVES: To describe the quality of pediatric resuscitative care in general emergency departments (GEDs) and to determine hospital-level factors associated with higher quality. METHODS: Prospective observational study of resuscitative care provided to 3 in situ simulated patients (infant seizure, infant sepsis, and child cardiac arrest) by interprofessional GED teams. A composite quality score (CQS) was measured and the association of this score with modifiable and nonmodifiable hospital-level factors was explored. RESULTS: A median CQS of 62.8 of 100 (interquartile range 50.5-71.1) was noted for 287 resuscitation teams from 175 emergency departments. In the unadjusted analyses, a higher score was associated with the modifiable factor of an affiliation with a pediatric academic medical center (PAMC) and the nonmodifiable factors of higher pediatric volume and location in the Northeast and Midwest. In the adjusted analyses, a higher CQS was associated with modifiable factors of an affiliation with a PAMC and the designation of both a nurse and physician pediatric emergency care coordinator, and nonmodifiable factors of higher pediatric volume and location in the Northeast and Midwest. A weak correlation was noted between quality and pediatric readiness scores. CONCLUSIONS: A low quality of pediatric resuscitative care, measured using simulation, was noted across a cohort of GEDs. Hospital factors associated with higher quality included: an affiliation with a PAMC, designation of a pediatric emergency care coordinator, higher pediatric volume, and geographic location. A weak correlation was noted between quality and pediatric readiness scores

FMRP targets distinct mRNA sequence elements to regulate protein expression

Fragile-X Syndrome (FXS) is a multi-organ disease leading to mental retardation, macro-orchidism in males, and premature ovarian insufficiency in female carriers. FXS is also a prominent monogenic disease associated with autism spectrum disorders (ASD). FXS is typically caused by the loss of FRAGILE X-MENTAL RETARDATION 1 (FMR1) expression, which encodes for the RNA-binding protein (RBP), FMRP. We report the discovery of distinct RNA recognition elements (RREs) that correspond to the two independent RNA binding domains of FMRP, and the binding sites within the mRNA targets for wild-type and I304N mutant FMRP isoforms and its paralogs, FXR1 and FXR2. RRE frequency, ratio, and distribution determine target mRNA association with FMRP. Among highly-enriched targets, we identified many genes involved in ASD and demonstrate that FMRP affects their protein levels in cell culture, mice, and human brain. Unexpectedly, we discovered that these targets are also dysregulated in Fmr1(-/-) mouse ovaries, showing signs of premature follicular overdevelopment. These results indicate that FMRP targets shared signaling pathways across different cellular contexts. As it is become increasingly appreciated that signaling pathways are important to FXS and ASD, our results here provide a molecular guide towards the pursuit of novel therapeutic targets for these neurological disorders