An allosteric inhibitor of RhoGAP class-IX myosins suppresses the metastatic features of cancer cells.

Aberrant Ras homologous (Rho) GTPase signalling is a major driver of cancer metastasis, and GTPase-activating proteins (GAPs), the negative regulators of RhoGTPases, are considered promising targets for suppressing metastasis, yet drug discovery efforts have remained elusive. Here, we report the identification and characterization of adhibin, a synthetic allosteric inhibitor of RhoGAP class-IX myosins that abrogates ATPase and motor function, suppressing RhoGTPase-mediated modes of cancer cell metastasis. In human and murine adenocarcinoma and melanoma cell models, including three-dimensional spheroid cultures, we reveal anti-migratory and anti-adhesive properties of adhibin that originate from local disturbances in RhoA/ROCK-regulated signalling, affecting actin-dynamics and actomyosin-based cell-contractility.

Crystal structures of cables formed by the acetylated and unacetylated forms of the Schizosaccharomyces pombe tropomyosin ortholog Tpm.

Cables formed by head-to-tail polymerization of tropomyosin, localized along the length of sarcomeric and cytoskeletal actin filaments, play a key role in regulating a wide range of motile and contractile processes. The stability of tropomyosin cables, their interaction with actin filaments and the functional properties of the resulting co-filaments are thought to be affected by N-terminal acetylation of tropomyosin. Here, we present high-resolution structures of cables formed by acetylated and unacetylated Schizosaccharomyces pombe tropomyosin ortholog Tpm.

Biochemical characterization of cardiac α-actin mutations A21V and D26N implicated in hypertrophic cardiomyopathy.

Familial hypertrophic cardiomyopathy (HCM) affects .2% of the world's population and is inherited in an autosomal dominant manner. Mutations in cardiac α-actin are the cause in 1%-5% of all observed cases.

The non-muscle actinopathy-associated mutation E334Q in cytoskeletal γ-actin perturbs interaction of actin filaments with myosin and ADF/cofilin family proteins.

Various heterozygous cytoskeletal γ-actin mutations have been shown to cause Baraitser-Winter cerebrofrontofacial syndrome, non-syndromic hearing loss, or isolated eye coloboma. Here, we report the biochemical characterization of human cytoskeletal γ-actin carrying mutation E334Q, a mutation that leads to a hitherto unspecified non-muscle actinopathy. Following expression, purification, and removal of linker and thymosin β4 tag sequences, the p.

Neural correlates of semantic-driven syntactic parsing in sentence comprehension.

For sentence comprehension, information carried by semantic relations between constituents must be combined with other information to decode the constituent structure of a sentence, due to atypical and noisy situations of language use. Neural correlates of decoding sentence structure by semantic information have remained largely unexplored. In this functional MRI study, we examine the neural basis of semantic-driven syntactic parsing during sentence reading and compare it with that of other types of syntactic parsing driven by word order and case marking.

Extending the enzymatic toolbox for heparosan polymerization, depolymerization, and detection.

Heparosan is an acidic polysaccharide expressed as a capsule polymer by pathogenic and commensal bacteria, e.g. by E.

Morphological decomposition in Chinese compound word recognition: Electrophysiological evidence.

The present study examined the effect of both morphological complexity and semantic transparency in Chinese compound word recognition. Using a visual lexical decision task, our electrophysiological results showed that transparent and opaque compounds induced stronger Left Anterior Negativity (LAN) than monomorphemic words. This result suggests that Chinese compounds might be decomposed into their constituent morphemes at the lemma level, whereas monomorphemic words are accessed as a whole-word lemma directly from the form level.

Equity in Receipt of a Lumbar Puncture for Febrile Infants at an Academic Center.

Background: The evaluation of febrile infants ≤60 days of age is often guided by established protocols. However, structural racism and physicians' implicit bias may affect how such clinical guidelines are applied.

Objective: To determine the association between self-identified race, insurance type, ZIP code-based median household income (MHI) and receiving a guideline-concordant lumbar puncture (GCLP) in febrile infants.

Parent-in-training: Resident and fellow experiences from pregnancy to parenthood.

Background: Residents and fellows with children face distinct challenges; however, knowledge of factors associated with increased parental stress is limited.

Objective: This study aimed to investigate experiences and concerns of physician trainees and identify factors associated with higher parental stress.

Methods: An anonymous survey was distributed to all resident and fellow trainees in June 2021 to assess experiences regarding parental leave, breastfeeding, and childcare.

Distinct actin-tropomyosin cofilament populations drive the functional diversification of cytoskeletal myosin motor complexes.

The effects of N-terminal acetylation of the high molecular weight tropomyosin isoforms Tpm1.6 and Tpm2.1 and the low molecular weight isoforms Tpm1.

Meteorin-like promotes heart repair through endothelial KIT receptor tyrosine kinase.

Effective tissue repair after myocardial infarction entails a vigorous angiogenic response, guided by incompletely defined immune cell-endothelial cell interactions. We identify the monocyte- and macrophage-derived cytokine METRNL (meteorin-like) as a driver of postinfarction angiogenesis and high-affinity ligand for the stem cell factor receptor KIT (KIT receptor tyrosine kinase). METRNL mediated angiogenic effects in cultured human endothelial cells through KIT-dependent signaling pathways.

Frameshift mutation S368fs in the gene encoding cytoskeletal β-actin leads to ACTB-associated syndromic thrombocytopenia by impairing actin dynamics.

Heterozygous dominant mutations in the ubiquitously produced cytoskeletal β-actin isoform lead to a broad range of human disease phenotypes, which are currently classified as three distinct clinical entities termed Baraitser-Winter-Cerebrofrontofacial syndrome (BWCFF), ACTB-associated pleiotropic malformation syndrome with intellectual disability (ACTB-PMSID), and ACTB-associated syndromic thrombocytopenia (ACTB-AST). The latter two are distinguishable from BWCFF by the presence of milder craniofacial features and less pronounced developmental abnormalities, or the absence of craniofacial features in combination with a characteristic thrombocytopenia with platelet anisotropy. Production and correct function of β-actin is required for multiple essential processes in all types of cells.

Assessment of the Contribution of a Thermodynamic and Mechanical Destabilization of Myosin-Binding Protein C Domain C2 to the Pathomechanism of Hypertrophic Cardiomyopathy-Causing Double Mutation .

Mutations in the gene encoding cardiac myosin-binding protein-C (MyBPC), a thick filament assembly protein that stabilizes sarcomeric structure and regulates cardiac function, are a common cause for the development of hypertrophic cardiomyopathy. About 10% of carriers of the Δ25bp variant of , which is common in individuals from South Asia, are also carriers of the D389V variant on the same allele. Compared with noncarriers and those with alone, indicators for the development of hypertrophic cardiomyopathy occur with increased frequency in carriers.

Structural and Biochemical Characterization of a Dye-Decolorizing Peroxidase from .

A novel cytoplasmic dye-decolorizing peroxidase from was investigated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such as ABTS efficiently. Unlike related enzymes, an aspartate residue replaces the first glycine of the conserved GXXDG motif in DyPA. In solution, DyPA exists as a stable dimer with the side chain of Asp146 contributing to the stabilization of the dimer interface by extending the hydrogen bond network connecting two monomers.

Allosteric modulation of cardiac myosin mechanics and kinetics by the conjugated omega-7,9 trans-fat rumenic acid.

Key Points: Direct binding of rumenic acid to the cardiac myosin-2 motor domain increases the release rate for orthophosphate and increases the Ca responsiveness of cardiac muscle at low load. Physiological cellular concentrations of rumenic acid affect the ATP turnover rates of the super-relaxed and disordered relaxed states of β-cardiac myosin, leading to a net increase in myocardial metabolic load. In Ca -activated trabeculae, rumenic acid exerts a direct inhibitory effect on the force-generating mechanism without affecting the number of force-generating motors.

Muscle myosin performance measured with a synthetic nanomachine reveals a class-specific Ca -sensitivity of the frog myosin II isoform.

Key Points: A nanomachine made of an ensemble of seven heavy-meromyosin (HMM) fragments of muscle myosin interacting with an actin filament is able to mimic the half-sarcomere generating steady force and constant-velocity shortening. To preserve Ca as a free parameter, the Ca -insensitive gelsolin fragment TL40 is used to attach the correctly oriented actin filament to the laser-trapped bead acting as a force transducer. The new method reveals that the performance of the nanomachine powered by myosin from frog hind-limb muscles depends on [Ca ], an effect mediated by a Ca -binding site in the regulatory light chain of HMM.

Association of Bacteremia with Vaccination Status in Children Aged 2 to 36 Months.

Objective: To determine the association between bacteremia and vaccination status in children aged 2-36 months presenting to a pediatric emergency department.

Study Design: Retrospective cohort study of children aged 2-36 months with blood cultures obtained in the pediatric emergency department between January 2013 and December 2017. The exposure of interest was immunization status, defined as number of Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae vaccinations, and the main outcome positive blood culture.

Mechanochemical properties of human myosin-1C are modulated by isoform-specific differences in the N-terminal extension.

Myosin-1C is a single-headed, short-tailed member of the myosin class I subfamily that supports a variety of actin-based functions in the cytosol and nucleus. In vertebrates, alternative splicing of the MYO1C gene leads to the production of three isoforms, myosin-1C, myosin-1C, and myosin-1C, that carry N-terminal extensions of different lengths. However, it is not clear how these extensions affect the chemomechanical coupling of human myosin-1C isoforms.

Myosin-18B Regulates Higher-Order Organization of the Cardiac Sarcomere through Thin Filament Cross-Linking and Thick Filament Dynamics.

MYO18B loss-of-function mutations and depletion significantly compromise the structural integrity of striated muscle sarcomeres. The molecular function of the encoded protein, myosin-18B (M18B), within the developing muscle is unknown. Here, we demonstrate that recombinant M18B lacks motor ATPase activity and harbors previously uncharacterized N-terminal actin-binding domains, properties that make M18B an efficient actin cross-linker and molecular brake capable of regulating muscle myosin-2 contractile forces.

Myosin XVIII.

Class XVIII myosins represent a branch of the myosin family tree characterized by the presence of large N- and C-terminal extensions flanking a generic myosin core. These myosins display the highest sequence similarity to conventional class II muscle myosins and are compatible with but not restricted to myosin-2 contractile structures. Instead, they fulfill their functions at diverse localities, such as lamella, actomyosin bundles, the Golgi apparatus, focal adhesions, the cell membrane, and within sarcomeres.

C-mannosylation supports folding and enhances stability of thrombospondin repeats.

Previous studies demonstrated importance of C-mannosylation for efficient protein secretion. To study its impact on protein folding and stability, we analyzed both C-mannosylated and non-C-mannosylated thrombospondin type 1 repeats (TSRs) of netrin receptor UNC-5. In absence of C-mannosylation, UNC-5 TSRs could only be obtained at low temperature and a significant proportion displayed incorrect intermolecular disulfide bridging, which was hardly observed when C-mannosylated.

Phenamacril is a reversible and noncompetitive inhibitor of class I myosin.

The cyanoacrylate compound phenamacril (also known as JS399-19) is a recently identified fungicide that exerts its antifungal effect on susceptible species by inhibiting the ATPase activity of their myosin class I motor domains. Although much is known about the antifungal spectrum of phenamacril, the exact mechanism behind the phenamacril-mediated inhibition remains to be resolved. Here, we describe the characterization of the effect of phenamacril on purified myosin motor constructs from the model plant pathogen and phenamacril-susceptible species , phenamacril-resistant species, and the mycetozoan model organism Our results show that phenamacril potently (IC ∼360 nm), reversibly, and noncompetitively inhibits ATP turnover, actin binding during ATP turnover, and motor activity of myosin-1.