A summary of the 2023 Society of Obstetric Medicine of Australia and New Zealand (SOMANZ) hypertension in pregnancy guideline.

Introduction: Hypertensive disorders of pregnancy (HDP) affect up to 10% of all pregnancies annually and are associated with an increased risk of maternal and fetal morbidity and mortality. This guideline represents an update of the Society of Obstetric Medicine of Australia and New Zealand (SOMANZ) guidelines for the management of hypertensive disorders of pregnancy 2014 and has been approved by the National Health and Medical Research Council (NHMRC) under section 14A of the National Health and Medical Research Council Act 1992. In approving the guideline recommendations, NHMRC considers that the guideline meets NHMRC's standard for clinical practice guidelines.

The histone H3-H4 tetramer is a copper reductase enzyme.

Eukaryotic histone H3-H4 tetramers contain a putative copper (Cu) binding site at the H3-H3' dimerization interface with unknown function. The coincident emergence of eukaryotes with global oxygenation, which challenged cellular copper utilization, raised the possibility that histones may function in cellular copper homeostasis. We report that the recombinant H3-H4 tetramer is an oxidoreductase enzyme that binds Cu and catalyzes its reduction to Cu in vitro.

Anti-MDA5-associated dermatomyositis.

Anti-MDA5-associated dermatomyositis (MDA5-associated DM) is an uncommon presentation of idiopathic inflammatory myositis, typically amyopathic, associated with rapidly progressive, treatment refractory interstitial lung disease and poor prognosis, particularly in patients with concomitant rapidly progressive interstitial lung disease (RP-ILD). We report two cases of MDA5-associated DM with fatal outcome in one of the patients, despite 'aggressive triple therapy' for RP-ILD.

CryoEM structures of Arabidopsis DDR complexes involved in RNA-directed DNA methylation.

Transcription by RNA polymerase V (Pol V) in plants is required for RNA-directed DNA methylation, leading to transcriptional gene silencing. Global chromatin association of Pol V requires components of the DDR complex DRD1, DMS3 and RDM1, but the assembly process of this complex and the underlying mechanism for Pol V recruitment remain unknown. Here we show that all DDR complex components co-localize with Pol V, and we report the cryoEM structures of two complexes associated with Pol V recruitment-DR (DMS3-RDM1) and DDR' (DMS3-RDM1-DRD1 peptide), at 3.

The Gene-Silencing Protein MORC-1 Topologically Entraps DNA and Forms Multimeric Assemblies to Cause DNA Compaction.

Microrchidia (MORC) ATPases are critical for gene silencing and chromatin compaction in multiple eukaryotic systems, but the mechanisms by which MORC proteins act are poorly understood. Here, we apply a series of biochemical, single-molecule, and cell-based imaging approaches to better understand the function of the Caenorhabditis elegans MORC-1 protein. We find that MORC-1 binds to DNA in a length-dependent but sequence non-specific manner and compacts DNA by forming DNA loops.

A DNA methylation reader complex that enhances gene transcription.

DNA methylation generally functions as a repressive transcriptional signal, but it is also known to activate gene expression. In either case, the downstream factors remain largely unknown. By using comparative interactomics, we isolated proteins in that associate with methylated DNA.

Mouse MORC3 is a GHKL ATPase that localizes to H3K4me3 marked chromatin.

Microrchidia (MORC) proteins are GHKL (gyrase, heat-shock protein 90, histidine kinase, MutL) ATPases that function in gene regulation in multiple organisms. Animal MORCs also contain CW-type zinc finger domains, which are known to bind to modified histones. We solved the crystal structure of the murine MORC3 ATPase-CW domain bound to the nucleotide analog AMPPNP (phosphoaminophosphonic acid-adenylate ester) and in complex with a trimethylated histone H3 lysine 4 (H3K4) peptide (H3K4me3).

EP400 Deposits H3.3 into Promoters and Enhancers during Gene Activation.

Gene activation in metazoans is accompanied by the presence of histone variants H2AZ and H3.3 within promoters and enhancers. It is not known, however, what protein deposits H3.

Transcriptional gene silencing by Arabidopsis microrchidia homologues involves the formation of heteromers.

Epigenetic gene silencing is of central importance to maintain genome integrity and is mediated by an elaborate interplay between DNA methylation, histone posttranslational modifications, and chromatin remodeling complexes. DNA methylation and repressive histone marks usually correlate with transcriptionally silent heterochromatin, however there are exceptions to this relationship. In Arabidopsis, mutation of Morpheus Molecule 1 (MOM1) causes transcriptional derepression of heterochromatin independently of changes in DNA methylation.

Inhibition of a NEDD8 Cascade Restores Restriction of HIV by APOBEC3G.

Cellular restriction factors help to defend humans against human immunodeficiency virus (HIV). HIV accessory proteins hijack at least three different Cullin-RING ubiquitin ligases, which must be activated by the small ubiquitin-like protein NEDD8, in order to counteract host cellular restriction factors. We found that conjugation of NEDD8 to Cullin-5 by the NEDD8-conjugating enzyme UBE2F is required for HIV Vif-mediated degradation of the host restriction factor APOBEC3G (A3G).

Vif hijacks CBF-β to degrade APOBEC3G and promote HIV-1 infection.

Restriction factors, such as the retroviral complementary DNA deaminase APOBEC3G, are cellular proteins that dominantly block virus replication. The AIDS virus, human immunodeficiency virus type 1 (HIV-1), produces the accessory factor Vif, which counteracts the host's antiviral defence by hijacking a ubiquitin ligase complex, containing CUL5, ELOC, ELOB and a RING-box protein, and targeting APOBEC3G for degradation. Here we reveal, using an affinity tag/purification mass spectrometry approach, that Vif additionally recruits the transcription cofactor CBF-β to this ubiquitin ligase complex.