One RING to rule them all: Mind bomb-1 ccRING3 controls Notch signaling.

In this issue of Structure, Cao et al. use X-ray crystallography, biochemical, and genetic studies to define the key role of the Mind bomb-1 ccRING3 domain in triggering Notch signaling, and they demonstrate that ccRING3-mediated dimerization is a key step in ligand activation.

The dynamic hypoosmotic response of relies on the mechanosensitive channel MscS.

adapts to osmotic down-shifts by releasing metabolites through two mechanosensitive (MS) channels, low-threshold MscS and high-threshold MscL. To investigate each channel's contribution to the osmotic response, we generated , , and double mutants in O395. We characterized their tension-dependent activation in patch-clamp, and the millisecond-scale osmolyte release kinetics using a stopped-flow light scattering technique.

Unraveling paralog-specific Notch signaling through thermodynamics of ternary complex formation and transcriptional activation of chimeric receptors.

Notch signaling in humans is mediated by four paralogous receptors that share conserved architectures and possess overlapping, yet non-redundant functions. The receptors share a canonical activation pathway wherein upon extracellular ligand binding, the Notch intracellular domain (NICD) is cleaved from the membrane and translocates to the nucleus where its N-terminal RBP-j-associated molecule (RAM) region and ankyrin repeat (ANK) domain bind transcription factor CSL and recruit co-activator Mastermind-like-1 (MAML1) to activate transcription. However, different paralogs can lead to distinct outcomes.

Unit-Based Nurses' Development of a Couplet Care Acuity Scoring Tool.

Objective: To evaluate content validity (CV) and interrater reliability (IRR) of an acuity scoring tool developed for the couplet care/postpartum/nursery patient population and to determine if there was agreement between supervisor or director scoring and staff scoring.

Design: A scoring tool to assess the acuity of the couplet care/postpartum/nursery patients was developed.

Setting: Two hospitals: one Level 2 hospital, one Level 3 hospital.

Quality of Life Differences in Children and Adolescents With 0, 1 to 2, or 3+ Persistent Postconcussion Symptoms.

Context: Persistent postconcussion symptoms (PPCSs) are associated with lower health-related quality of life (HRQoL) in children and adolescents. Despite commonly cited criteria for PPCSs involving 3 or more complaints, many individuals experience just 1 or 2 symptoms that may still negatively affect HRQoL.

Objective: To determine differences in HRQoL between children and adolescents with 0, 1 to 2, or 3+ parent-reported persistent symptoms at 1 month postconcussion.

The dynamic hypoosmotic response of Vibrio cholerae relies on the mechanosensitive channel MscS.

Like other intestinal bacteria, the facultative pathogen Vibrio cholerae adapts to a wide range of osmotic environments. Under drastic osmotic down-shifts, Vibrio avoids mechanical rupture by rapidly releasing excessive metabolites through mechanosensitive (MS) channels that belong to two major types, low-threshold MscS and high-threshold MscL. To investigate each channel individual contribution to V.

Individual Symptom Report Prevalence in Children and Adolescents With One, Two, and Three or More Persistent Symptoms After Concussion: A Brief Report.

Objective: To examine differences in individual symptom report prevalence between children and adolescents experiencing 1 to 2 versus ≥3 persistent postconcussion symptoms.

Design: A prospective cohort study.

Setting: Three community practice concussion clinics within a family practice network.

Presence of Persistent Parent Reported Emotional and Behavioral-Related Concussion Symptoms Is Associated with Lower Health-Related Quality of Life in Adolescent Athletes.

Persistent concussion symptoms in adolescents are associated with lower health-related quality of life (HRQOL). The association between persistent emotional and behavioral-related concussion symptoms (EBS) and HRQOL is unknown, however. This study was a prospective cohort of adolescent athletes presenting to a concussion clinic within three days post-concussion and completing a one-month follow-up.

Exclusivity and Compensation in NFκB Dimer Distributions and IκB Inhibition.

The NFκB transcription factor family members RelA, p50, and cRel form homo- and heterodimers that are inhibited by IκBα, IκBβ, and IκBε. These NFκB family members have diverse biological functions, and their expression profiles differ, leading to different concentrations in different tissue types. Here we present definitive biophysical measurements of the NFκB dimer affinities and inhibitor affinities to better understand dimer exchange and how the presence of inhibitors may alter the equilibrium concentrations of NFκB dimers in the cellular context.

Prediction of the presence of a seventh ankyrin repeat in IκBε from homology modeling combined with hydrogen-deuterium exchange mass spectrometry (HDX-MS).

The ankyrin repeat (AR) structure is a common protein-protein interaction motif and ankyrin repeat proteins comprise a vast family across a large array of different taxa. Natural AR proteins adopt a conserved fold comprised of several repeats with the N- and C-terminal repeats generally being of more divergent sequences. Obtaining experimental crystal structures for natural ankyrin repeat domains (ARD) can be difficult and often requires complexation with a binding partner.

RNAs interact with BRD4 to promote enhanced chromatin engagement and transcription activation.

The bromodomain and extra-terminal motif (BET) protein BRD4 binds to acetylated histones at enhancers and promoters via its bromodomains (BDs) to regulate transcriptional elongation. In human colorectal cancer cells, we found that BRD4 was recruited to enhancers that were co-occupied by mutant p53 and supported the synthesis of enhancer-directed transcripts (eRNAs) in response to chronic immune signaling. BRD4 selectively associated with eRNAs that were produced from BRD4-bound enhancers.

DNA and IκBα Both Induce Long-Range Conformational Changes in NFκB.

We recently discovered that IκBα enhances the rate of release of nuclear factor kappa B (NFκB) from DNA target sites in a process we have termed molecular stripping. Coarse-grained molecular dynamics simulations of the stripping pathway revealed two mechanisms for the enhanced release rate: the negatively charged PEST region of IκBα electrostatically repels the DNA, and the binding of IκBα appears to twist the NFκB heterodimer so that the DNA can no longer bind. Here, we report amide hydrogen/deuterium exchange data that reveal long-range allosteric changes in the NFκB (RelA-p50) heterodimer induced by DNA or IκBα binding.

Binding of NFκB Appears to Twist the Ankyrin Repeat Domain of IκBα.

Total internal reflection fluorescence-based single-molecule Förster resonance energy transfer (FRET) measurements were previously carried out on the ankyrin repeat domain (ARD) of IκBα, the temporally regulated inhibitor of canonical NFκB signaling. Under native conditions, most of the IκBα molecules showed stable, high FRET signals consistent with distances between the fluorophores estimated from the crystal structures of the NFκB(RelA/p50)-IκBα complex. Similar high FRET efficiencies were found when the IκBα molecules were either free or in complex with NFκB(RelA/p50), and were interpreted as being consistent with the crystallographically observed ARD structure.

Dual allosteric activation mechanisms in monomeric human glucokinase.

Cooperativity in human glucokinase (GCK), the body's primary glucose sensor and a major determinant of glucose homeostatic diseases, is fundamentally different from textbook models of allostery because GCK is monomeric and contains only one glucose-binding site. Prior work has demonstrated that millisecond timescale order-disorder transitions within the enzyme's small domain govern cooperativity. Here, using limited proteolysis, we map the site of disorder in unliganded GCK to a 30-residue active-site loop that closes upon glucose binding.