Acetyl-Click Screening Platform Identifies Small-Molecule Inhibitors of Histone Acetyltransferase 1 (HAT1).

HAT1 is a central regulator of chromatin synthesis that acetylates nascent histone H4. To ascertain whether targeting HAT1 is a viable anticancer treatment strategy, we sought to identify small-molecule inhibitors of HAT1 by developing a high-throughput HAT1 acetyl-click assay. Screening of small-molecule libraries led to the discovery of multiple riboflavin analogs that inhibited HAT1 enzymatic activity.

Mitochondrial Uncoupling Induces Epigenome Remodeling and Promotes Differentiation in Neuroblastoma.

Unlabelled: The Warburg effect is the major metabolic hallmark of cancer. According to Warburg himself, the consequence of the Warburg effect is cell dedifferentiation. Therefore, reversing the Warburg effect might be an approach to restore cell differentiation in cancer.

Conformational Rearrangements Regulating the DNA Repair Protein APE1.

Apurinic apyrimidinic endonuclease 1 (APE1) is a key enzyme of the Base Excision Repair (BER) pathway, which primarily manages oxidative lesions of DNA. Once the damaged base is removed, APE1 recognises the resulting abasic site and cleaves the phosphodiester backbone to allow for the correction by subsequent enzymes of the BER machinery. In spite of a wealth of information on APE1 structure and activity, its regulation mechanism still remains to be understood.

Transition cow metabolites and physical traits influence days to first postpartum ovulation in dairy cows.

Physical activities are associated with the health of transition dairy cows and pregnancy outcomes are positively related to early resumption of postpartum estrous cycles. The objective was to assess key metabolites and patterns of prepartum and postpartum physical activity as they relate to the onset of first postpartum ovulation in lactating dairy cows. Close-up dry Holstein cows (n = 82) and late gestation heifers (n = 78) were enrolled beginning 3 wk before expected calving date (Day 0).

Molecular Mechanisms Regulating the DNA Repair Protein APE1: A Focus on Its Flexible N-Terminal Tail Domain.

APE1 (DNA (apurinic/apyrimidinic site) endonuclease 1) is a key enzyme of one of the major DNA repair routes, the BER (base excision repair) pathway. APE1 fulfils additional functions, acting as a redox regulator of transcription factors and taking part in RNA metabolism. The mechanisms regulating APE1 are still being deciphered.

Nucleophosmin, a multifunctional nucleolar organizer with a role in DNA repair.

Nucleophosmin (NPM1) is a mostly nucleolar protein with crucial functions in cell growth and homeostasis, including regulation of ribosome biogenesis and stress response. Such multiple activities rely on its ability to interact with nucleic acids and with hundreds of proteins, as well as on a dynamic subcellular distribution. NPM1 is thus regulated by a complex interplay between localization and interactions, further modulated by post-translational modifications.

Transition dairy cow health is associated with first postpartum ovulation risk, metabolic status, milk production, rumination, and physical activity.

Our objective was to determine the association of health status during the first 60 d in milk (DIM) and first postpartum ovulation risk, physical activities recorded by an activity monitor, and metabolic and milk measures in Holstein cows. Late-gestation heifers and close-up dry cows in 1 herd fitted with CowManager SensOors (Agis, Harmelen, the Netherlands) were enrolled in the study 3 wk before expected parturition to assess ear skin temperature and daily rumination, eating, inactivity, and activity times. Blood samples were collected at calving (d 0), and on d 3, 7, and 14 to assess concentrations of free fatty acids, β-hydroxybutyrate (BHB), calcium, glucose, and haptoglobin.

Conserved Ark1-related kinases function in a TORC2 signaling network.

In all orders of life, cell cycle progression in proliferating cells is dependent on cell growth, and the extent of growth required for cell cycle progression is proportional to growth rate. Thus, cells growing rapidly in rich nutrients are substantially larger than slow-growing cells. In budding yeast, a conserved signaling network surrounding Tor complex 2 (target of rapamycin complex 2; TORC2) controls growth rate and cell size in response to nutrient availability.

Physiologic responses to feeding rumen-protected glucose to lactating dairy cows.

It was hypothesized that rumen-protected glucose (RPG) in diets of dairy cows increases concentrations of insulin resulting in greater blood progesterone concentrations because elevated insulin decreases activity of liver enzymes inactivating steroid hormones. Timing of ovulation was synchronized among 64 postpartum Holstein cows using GnRH and PGF (Day 0 = ovulation). Cows were milked thrice daily and assigned randomly a basal diet supplemented with 0, 1, 2, or 4 kg of an RPG product in place of corn grain, top-dressed in the diet beginning on Day -3.

Nucleophosmin interaction with APE1: Insights into DNA repair regulation.

Nucleophosmin (NPM1), an abundant, nucleolar protein with multiple functions affecting cell homeostasis, has also been recently involved in DNA damage repair. The roles of NPM1 in different repair pathways remain however to be elucidated. NPM1 has been described to interact with APE1 (apurinic apyrimidinic endonuclease 1), a key enzyme of the base excision repair (BER) pathway, which could reflect a direct participation of NPM1 in this route.

Modeling the long term effects of thermoregulation on human sleep.

The connection between human sleep and energy exertion has long been regarded as part of the reasoning for the need to sleep. A recent theory proposes that during REM sleep, energy utilized for thermoregulation is diverted to other relevant biological processes. We present a mathematical model of human sleep/wake regulation with thermoregulatory functions to gain quantitative insight into the effects of ambient temperature on sleep quality.

Conformational stabilization as a strategy to prevent nucleophosmin mislocalization in leukemia.

Nucleophosmin (NPM) is a nucleolar protein involved in ribosome assembly and cell homeostasis. Mutations in the C-terminal domain of NPM that impair native folding and localization are associated with acute myeloid leukemia (AML). We have performed a high-throughput screening searching for compounds that stabilize the C-terminal domain.

A cellular reporter to evaluate CRM1 nuclear export activity: functional analysis of the cancer-related mutant E571K.

The exportin CRM1 binds nuclear export signals (NESs), and mediates active transport of NES-bearing proteins from the nucleus to the cytoplasm. Structural and biochemical analyses have uncovered the molecular mechanisms underlying CRM1/NES interaction. CRM1 binds NESs through a hydrophobic cleft, whose open or closed conformation facilitates NES binding and release.

Leukemia-Associated Mutations in Nucleophosmin Alter Recognition by CRM1: Molecular Basis of Aberrant Transport.

Nucleophosmin (NPM) is a nucleocytoplasmic shuttling protein, normally enriched in nucleoli, that performs several activities related to cell growth. NPM mutations are characteristic of a subtype of acute myeloid leukemia (AML), where mutant NPM seems to play an oncogenic role. AML-associated NPM mutants exhibit altered subcellular traffic, being aberrantly located in the cytoplasm of leukoblasts.

Recognition of intermolecular G-quadruplexes by full length nucleophosmin. Effect of a leukaemia-associated mutation.

Nucleophosmin (NPM) is a nucleolar protein involved in ribosome biogenesis. NPM1 gene is frequently mutated in acute myeloid leukaemia (AML), correlating with aberrant cytoplasmic localization of the protein. NPM attachment to the nucleolus in physiological conditions probably depends on binding to nucleic acids, and this recognition could be altered in AML.

A global survey of CRM1-dependent nuclear export sequences in the human deubiquitinase family.

The mechanisms that regulate the nucleocytoplasmic localization of human deubiquitinases remain largely unknown. The nuclear export receptor CRM1 binds to specific amino acid motifs termed NESs (nuclear export sequences). By using in silico prediction and experimental validation of candidate sequences, we identified 32 active NESs and 78 inactive NES-like motifs in human deubiquitinases.

Simultaneous detection of ten psychedelic phenethylamines in urine by gas chromatography-mass spectrometry.

Psychedelic phenethylamines are an emerging class of designer drugs capable of producing a complex array of sought after adrenergic and hallucinogenic effects. Toxicological detection poses a number of challenges to laboratories. The purpose of this study was to develop a procedure for the detection of psychedelic amphetamines using techniques that are widely accepted in forensic toxicology laboratories.

Evaluation of commercial enzyme-linked immunosorbent assays to identify psychedelic phenethylamines.

The 2C, 2C-T, and DO series of designer drugs pose a number of challenges to forensic toxicology laboratories. Although these drugs are seized by law enforcement agencies throughout the United States, they are not readily detected in forensic toxicology laboratories. A systematic evaluation of the cross-reactivity of 9 commercial enzyme-linked immunosorbent assays (ELISAs) was conducted using 11 designer drugs.

The nuclear transport machinery recognizes nucleoplasmin-histone complexes.

The nuclear transport of the chromatin remodeling protein nucleoplasmin and chromatin building histones is mediated by importins. Nucleoplasmin (NP) contains a classical bipartite nuclear localization signal (NLS) that is recognized by the importin α/β heterodimer, while histones present multiple NLS-like motifs that are recognized by importin β family members for nuclear targeting. To explore the possibility of a cotransport of histones and their chaperone NP to the nucleus, we have analyzed the assembly of complexes of NP/histones with importins by means of fluorescence anisotropy, centrifugation in sucrose gradients, and isothermal titration calorimetry.

Active rehabilitation and physical therapy during extracorporeal membrane oxygenation while awaiting lung transplantation: a practical approach.

Objective: Extracorporeal membrane oxygenation as a bridge to lung transplantation has traditionally been associated with substantial morbidity and mortality. A major contributor to these complications may be weakness and overall deconditioning secondary to pretransplant critical illness and immobility. In an attempt to address this issue, we developed a collaborative program to allow for active rehabilitation and physical therapy for patients requiring life support with extracorporeal membrane oxygenation before lung transplantation.

Recognition of nucleoplasmin by its nuclear transport receptor importin α/β: insights into a complete import complex.

Nuclear import of the pentameric histone chaperone nucleoplasmin (NP) is mediated by importin α, which recognizes its nuclear localization sequence (NLS), and importin β, which interacts with α and is in charge of the translocation of the NP/α/β complex through the nuclear pore. Herein, we characterize the assembly of a functional transport complex formed by full-length NP with importin α/β. Isothermal titration calorimetry (ITC) was used to analyze the thermodynamics of the interactions of importin α with β, α with NP, and the α/β heterodimer with NP.

A mechanism for histone chaperoning activity of nucleoplasmin: thermodynamic and structural models.

Nucleoplasmin (NP), a histone chaperone, acts as a reservoir for histones H2A-H2B in Xenopus laevis eggs and can displace sperm nuclear basic proteins and linker histones from the chromatin fiber of sperm and quiescent somatic nuclei. NP has been proposed to mediate the dynamic exchange of histones during the expression of certain genes and assists the assembly of nucleosomes by modulating the interaction between histones and DNA. Here, solution structural models of full-length NP and NP complexes with the functionally distinct nucleosomal core and linker histones are presented for the first time, providing a picture of the physical interactions between the nucleosomal and linker histones with NP core and tail domains.

Activation of nucleoplasmin, an oligomeric histone chaperone, challenges its stability.

Nucleoplasmin (NP) is a pentameric, ring-shaped histone chaperone involved in chromatin remodeling processes such as sperm decondensation at fertilization. Monomers are formed by a core domain, responsible for oligomerization, that confers the protein a high stability and compactness and a flexible tail domain, that harbors a polyglutamic tract and the nuclear localization signal. Fully activated NP presents multiple phosphorylated residues in the tail and in flexible regions of the core domain.

Decreased body mass index and restrictive lung disease in congenital thoracic scoliosis.

Background: Pediatric patients with congenital thoracic scoliosis often have restrictive lung disease and low body weight for age. In other patients with respiratory disorders, the work of breathing can increase basal metabolic demands and predispose patients to cachexia. The primary study aim was to determine if severity of restrictive lung disease, as measured by pulmonary spirometry, correlates to decreased body mass index (BMI) in patients with congenital thoracic scoliosis.