Actin binding to WH2 domains regulates nuclear import of the multifunctional actin regulator JMY

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology of the Cell 23 (2012): 853-863, doi:10.1091/mbc.E11-12-0992.Junction-mediating and regulatory protein (JMY) is a regulator of both transcription and actin filament assembly. In response to DNA damage, JMY accumulates in the nucleus and promotes p53-dependent apoptosis. JMY's actin-regulatory activity relies on a cluster of three actin-binding Wiskott–Aldrich syndrome protein homology 2 (WH2) domains that nucleate filaments directly and also promote nucleation activity of the Arp2/3 complex. In addition to these activities, we find that the WH2 cluster overlaps an atypical, bipartite nuclear localization sequence (NLS) and controls JMY's subcellular localization. Actin monomers bound to the WH2 domains block binding of importins to the NLS and prevent nuclear import of JMY. Mutations that impair actin binding, or cellular perturbations that induce actin filament assembly and decrease the concentration of monomeric actin in the cytoplasm, cause JMY to accumulate in the nucleus. DNA damage induces both cytoplasmic actin polymerization and nuclear import of JMY, and we find that damage-induced nuclear localization of JMY requires both the WH2/NLS region and importin β. On the basis of our results, we propose that actin assembly regulates nuclear import of JMY in response to DNA damage.This work was supported by grants from the National Institutes of Health, an American Heart Association Predoctoral Fellowship (J.B.Z.), the Robert Day Allen Fellowship Fund (J.B.Z.), and a National Science Foundation Predoctoral Fellowship (B.B.)

NR5A1 gene variants repress the ovarian-specific WNT signaling pathway in 46,XX disorders of sex development patients

Several recent reports have described a missense variant in the gene NR5A1 (c.274C>T; p.Arg92Trp) in a significant number of 46,XX ovotesticular or testicular disorders of sex development (DSDs) cases. The affected residue falls within th

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Ovotesticular disorders of sex development in FGF9 mouse models of human synostosis syndromes

In mice, male sex determination depends on FGF9 signalling via FGFR2c in the bipotential gonads to maintain the expression of the key testis gene SOX9. In humans, however, while FGFR2 mutations have been linked to 46,XY disorders of sex development (DSD), the role of FGF9 is unresolved. The only reported pathogenic mutations in human FGF9, FGF9S99N and FGF9R62G, are dominant and result in craniosynostosis (fusion of cranial sutures) or multiple synostoses (fusion of limb joints). Whether these synostosis-causing FGF9 mutations impact upon gonadal development and DSD etiology has not been explored. We therefore examined embryonic gonads in the well-characterized Fgf9 missense mouse mutants, Fgf9S99N and Fgf9N143T, which phenocopy the skeletal defects of FGF9S99N and FGF9R62G variants, respectively. XY Fgf9S99N/S99N and XY Fgf9N143T/N143T fetal mouse gonads showed severely disorganized testis cords and partial XY sex reversal at 12.5\ua0days post coitum (dpc), suggesting loss of FGF9 function. By 15.5 dpc, testis development in both mutants had partly recovered. Mitotic analysis in vivo and in vitro suggested that the testicular phenotypes in these mutants arise in part through reduced proliferation of the gonadal supporting cells. These data raise the possibility that human FGF9 mutations causative for dominant skeletal conditions can also lead to loss of FGF9 function in the developing testis, at least in mice. Our data suggest that, in humans, testis development is largely tolerant of deleterious FGF9 mutations which lead to skeletal defects, thus offering an explanation as to why XY DSDs are rare in patients with pathogenic FGF9 variants

Human sex reversal is caused by duplication or deletion of core enhancers upstream of SOX9

SRY and its target SOX9 are known key determinants in testis development. Here the authors by studying duplications and deletions upstream of SOX9 from patient samples with disorders of sex development (DSD) reveal enhancers for SOX9 critical for human sex development and DSD