Complete genome sequence of Pseudomonas aeruginosa PAO1, an opportunistic pathogen

Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P. aeruginosa strain PAO1. At 6.3 million base pairs, this is the largest bacterial genome sequenced, and the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds as well as four potential chemotaxis systems. We propose that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.

The nanomechanical signature of breast cancer

Cancer initiation and progression follow complex molecular and structural changes in the extracellular matrix and cellular architecture of living tissue. However, it remains poorly understood how the transformation from health to malignancy alters the mechanical properties of cells within the tumour microenvironment. Here, we show using an indentation-type atomic force microscope (IT-AFM) that unadulterated human breast biopsies display distinct stiffness profiles. Correlative stiffness maps obtained on normal and benign tissues show uniform stiffness profiles that are characterized by a single distinct peak. In contrast, malignant tissues have a broad distribution resulting from tissue heterogeneity, with a prominent low-stiffness peak representative of cancer cells. Similar findings are seen in specific stages of breast cancer in MMTV-PyMT transgenic mice. Further evidence obtained from the lungs of mice with late-stage tumours shows that migration and metastatic spreading is correlated to the low stiffness of hypoxia-associated cancer cells. Overall, nanomechanical profiling by IT-AFM provides quantitative indicators in the clinical diagnostics of breast cancer with translational significance.

Tau Protein Disrupts Nucleocytoplasmic Transport in Alzheimer's Disease

Tau is the major constituent of neurofibrillary tangles in Alzheimer's disease (AD), but the mechanism underlying tau-associated neural damage remains unclear. Here, we show that tau can directly interact with nucleoporins of the nuclear pore complex (NPC) and affect their structural and functional integrity. Pathological tau impairs nuclear import and export in tau-overexpressing transgenic mice and in human AD brain tissue. Furthermore, the nucleoporin Nup98 accumulates in the cell bodies of some tangle-bearing neurons and can facilitate tau aggregation in vitro. These data support the hypothesis that tau can directly interact with NPC components, leading to their mislocalization and consequent disruption of NPC function. This raises the possibility that NPC dysfunction contributes to tau-induced neurotoxicity in AD and tauopathies.

Nanomechanical basis of selective gating by the nuclear pore complex

The nuclear pore complex regulates cargo transport between the cytoplasm and the nucleus. We set out to correlate the governing biochemical interactions to the nanoscopic responses of the phenylalanineglycine (FG)-rich nucleoporin domains, which are involved in attenuating or promoting cargo translocation. We found that binding interactions with the transport receptor karyopherin-beta1 caused the FG domains of the human nucleoporin Nup153 to collapse into compact molecular conformations. This effect was reversed by the action of Ran guanosine triphosphate, which returned the FG domains into a polymer brush-like, entropic barrier conformation. Similar effects were observed in Xenopus oocyte nuclei in situ. Thus, the reversible collapse of the FG domains may play an important role in regulating nucleocytoplasmic transport.

Flexible phenylalanine-glycine nucleoporins as entropic barriers to nucleocytoplasmic transport

Natively unfolded phenylalanine-glycine (FG)-repeat domains are alleged to form the physical constituents of the selective barrier-gate in nuclear pore complexes during nucleocytoplasmic transport. Presently, the biophysical mechanism behind the selective gate remains speculative because of a lack of information regarding the nanomechanical properties of the FG domains. In this work, we have applied the atomic force microscope to measure the mechanical response of individual and clusters of FG molecules. Single-molecule force spectroscopy reveals that FG molecules are unfolded and highly flexible. To provide insight into the selective gating mechanism, an experimental platform has been constructed to study the collective behavior of surface-tethered FG molecules at the nanoscale. Measurements indicate that the collective behavior of such FG molecules gives rise to an exponentially decaying long-range steric repulsive force. This finding indicates that the molecules are thermally mobile in an extended polymer brush-like conformation. This assertion is confirmed by observing that the brush-like conformation undergoes a reversible collapse transition in less polar solvent conditions. These findings reveal how FG-repeat domains may simultaneously function as an entropic barrier and a selective trap in the near-field interaction zone of nuclear pore complexes; i.e., selective gate.

Care homes' use of medicines study: prevalence, causes and potential harm of medication errors in care homes for older people

INTRODUCTION

Care home residents are at particular risk from medication errors, and our objective was to determine the prevalence and potential harm of prescribing, monitoring, dispensing and administration errors in UK care homes, and to identify their causes.

METHODS

A prospective study of a random sample of residents within a purposive sample of homes in three areas. Errors were identified by patient interview, note review, observation of practice and examination of dispensed items. Causes were understood by observation and from theoretically framed interviews with home staff, doctors and pharmacists. Potential harm from errors was assessed by expert judgement.

RESULTS

The 256 residents recruited in 55 homes were taking a mean of 8.0 medicines. One hundred and seventy-eight (69.5%) of residents had one or more errors. The mean number per resident was 1.9 errors. The mean potential harm from prescribing, monitoring, administration and dispensing errors was 2.6, 3.7, 2.1 and 2.0 (0 = no harm, 10 = death), respectively. Contributing factors from the 89 interviews included doctors who were not accessible, did not know the residents and lacked information in homes when prescribing; home staff's high workload, lack of medicines training and drug round interruptions; lack of team work among home, practice and pharmacy; inefficient ordering systems; inaccurate medicine records and prevalence of verbal communication; and difficult to fill (and check) medication administration systems.

CONCLUSIONS

That two thirds of residents were exposed to one or more medication errors is of concern. The will to improve exists, but there is a lack of overall responsibility. Action is required from all concerned.

Single-molecule transport across an individual biomimetic nuclear pore complex

Nuclear pore complexes regulate the selective exchange of RNA and proteins across the nuclear envelope in eukaryotic cells. Biomimetic strategies offer new opportunities to investigate this remarkable transport phenomenon. Here, we show selective transport of proteins across individual biomimetic nuclear pore complexes at the single-molecule level. Each biomimetic complex is constructed by covalently tethering either Nup98 or Nup153 (phenylalanine-glycine (FG) nucleoporins) to a solid-state nanopore. Individual translocation events are monitored using ionic current measurements with sub-millisecond temporal resolution. Transport receptors (Impβ) proceed with a dwell time of ∼2.5 ms for both Nup98- and Nup153-coated pores, whereas the passage of non-specific proteins is strongly inhibited with different degrees of selectivity. For pores up to ∼25 nm in diameter, Nups form a dense and low-conducting barrier, whereas they adopt a more open structure in larger pores. Our biomimetic nuclear pore complex provides a quantitative platform for studying nucleocytoplasmic transport phenomena at the single-molecule level in vitro.

Male breast carcinoma: a review of 229 patients who presented to the Princess Margaret Hospital during 40 years: 1955-1996

BACKGROUND

A single-institution review of clinical presentation, treatment, and outcome of male breast carcinoma was conducted.

METHODS

Data obtained by chart review of 229 cases were analyzed with respect to clinical presentation, treatment choice, significant prognostic factors, and survival. The patients were analyzed both as a single cohort and as four cohorts grouped according to decade of diagnosis.

RESULTS

Presentation occurred at a median age of 63 years, most often with a self-detected lump. Pathology consisted of subtypes similar to those of female breast carcinoma. The majority of tumors were larger than 2 cm in greatest dimension. Lymph node status, hormone receptors, and histologic and nuclear grade were underreported. Primary, adjuvant, and advanced disease treatment practices were reviewed over time. The 5-year disease free survival (DFS), overall survival (OS), and local control were 47%, 53%, and 91%, respectively. No difference in outcome by decade of diagnosis was observed. Negative lymph nodes and adjuvant hormone treatment predicted for better DFS and OS. Younger age and Stage 0 also predicted for better OS.

CONCLUSIONS

Compared with data from female breast carcinoma patients, 5-year OS for this series was low; however, when these patients were separated by lymph node status, survival was similar for those with axillary lymph node metastases. Despite a change in standard primary surgical treatment and an increased use of chemotherapy and hormone therapy over the study period, no difference in outcome was observed among these males. In the absence of prospective, randomized clinical trials, collection of comprehensive data on the presentation and management of male breast carcinoma may help to optimize clinical care.

Human GBP1 binds LPS to initiate assembly of a caspase-4 activating platform on cytosolic bacteria

The human non-canonical inflammasome controls caspase-4 activation and gasdermin-D-dependent pyroptosis in response to cytosolic bacterial lipopolysaccharide (LPS). Since LPS binds and oligomerizes caspase-4, the pathway is thought to proceed without dedicated LPS sensors or an activation platform. Here we report that interferon-induced guanylate-binding proteins (GBPs) are required for non-canonical inflammasome activation by cytosolic Salmonella or upon cytosolic delivery of LPS. GBP1 associates with the surface of cytosolic Salmonella seconds after bacterial escape from their vacuole, initiating the recruitment of GBP2-4 to assemble a GBP coat. The GBP coat then promotes the recruitment of caspase-4 to the bacterial surface and caspase activation, in absence of bacteriolysis. Mechanistically, GBP1 binds LPS with high affinity through electrostatic interactions. Our findings indicate that in human epithelial cells GBP1 acts as a cytosolic LPS sensor and assembles a platform for caspase-4 recruitment and activation at LPS-containing membranes as the first step of non-canonical inflammasome signaling.

Detection of LPS derived from Gram-negative bacteria by innate immune receptors is a critical step in the host response. Here Santos and colleagues show human GBP1 binds to LPS resulting in non-canonical inflammasome activation.

Quality of life in schizophrenia: contributions of anxiety and depression

A number of studies have demonstrated a strong relationship between quality of life in schizophrenia and general psychopathology measures, and moreover, that the positive, negative, and disorganized symptoms are less related to quality of life. The current investigation examined the relationship between quality of life and symptomatology in 63 stabilized outpatients diagnosed with schizophrenia or schizoaffective disorder. Consistent with other findings, more severe depression, as rated on the Brief Psychiatric Rating Scale (BPRS) was associated with lower general life satisfaction and lower satisfaction with daily living, finances, health, and social life. In addition, higher anxiety ratings on the BPRS were associated with less satisfaction with global quality of life, daily activities, family, health and social relationship, even when controlling for positive symptoms, negative symptoms, or depression. No other symptoms of schizophrenia were as strongly associated with subjective quality of life. Anxiety was also significantly correlated with a number of positive and negative symptoms while depression was substantially less related. These findings, suggest that more precise analyses of general psychopathology, and anxiety in particular, may be necessary to further clarify the factors involved in quality of life in schizophrenia. In addition, these findings suggest future directions for theories of affect and treatment in schizophrenia.

From adaptive licensing to adaptive pathways: delivering a flexible life-span approach to bring new drugs to patients

The concept of adaptive licensing (AL) has met with considerable interest. Yet some remain skeptical about its feasibility. Others argue that the focus and name of AL should be broadened. Against this background of ongoing debate, we examine the environmental changes that will likely make adaptive pathways the preferred approach in the future. The key drivers include: growing patient demand for timely access to promising therapies, emerging science leading to fragmentation of treatment populations, rising payer influence on product accessibility, and pressure on pharma/investors to ensure sustainability of drug development. We also discuss a number of environmental changes that will enable an adaptive paradigm. A life-span approach to bringing innovation to patients is expected to help address the perceived access vs. evidence trade-off, help de-risk drug development, and lead to better outcomes for patients.

Rat astrocytes and Schwann cells in culture synthesize nerve growth factor-like neurite-promoting factors

Neurite-promoting activity in feeding medium conditioned by rat astrocytes and Schwann cells in culture was examined. The conditioned medium (CM) from both types of glial cultures stimulated extensive neurite outgrowth from embryonic chick dorsal root ganglia (DRG) as well as pheochromocytoma (PC12) cells. Both the DRG and PC12 cells also produce neurite outgrowth in the presence of nerve growth factor (NGF). With the DRG, the neurite growth rates observed with the glial cell CM were identical to growth rates seen with NGF. Although anti-NGF antibody did not inhibit the neurite outgrowth produced by either of the glial CM, a nerve growth factor radioreceptor assay did detect an NGF-like molecule in both CM. Since the extensive neurite outgrowth stimulated by the glial CM was not mimicked by pure laminin alone, we conclude that the glial neurite promoting factors are distinct from laminin.

Spatiotemporal dynamics of the nuclear pore complex transport barrier resolved by high-speed atomic force microscopy

Nuclear pore complexes (NPCs) are biological nanomachines that mediate the bidirectional traffic of macromolecules between the cytoplasm and nucleus in eukaryotic cells. This process involves numerous intrinsically disordered, barrier-forming proteins known as phenylalanine-glycine nucleoporins (FG Nups) that are tethered inside each pore. The selective barrier mechanism has so far remained unresolved because the FG Nups have eluded direct structural analysis within NPCs. Here, high-speed atomic force microscopy is used to visualize the nanoscopic spatiotemporal dynamics of FG Nups inside Xenopus laevis oocyte NPCs at timescales of ∼100 ms. Our results show that the cytoplasmic orifice is circumscribed by highly flexible, dynamically fluctuating FG Nups that rapidly elongate and retract, consistent with the diffusive motion of tethered polypeptide chains. On this basis, intermingling FG Nups exhibit transient entanglements in the central channel, but do not cohere into a tightly crosslinked meshwork. Therefore, the basic functional form of the NPC barrier is comprised of highly dynamic FG Nups that manifest as a central plug or transporter when averaged in space and time.

Strongly stretched protein resistant poly(ethylene glycol) brushes prepared by grafting-to

We present a new grafting-to method for resistant "non-fouling" poly(ethylene glycol) brushes, which is based on grafting of polymers with reactive end groups in 0.9 M Na2SO4 at room temperature. The grafting process, the resulting brushes, and the resistance toward biomolecular adsorption are investigated by surface plasmon resonance, quartz crystal microbalance, and atomic force microscopy. We determine both grafting density and thickness independently and use narrow molecular weight distributions which result in well-defined brushes. High density (e.g., 0.4 coils per nm(2) for 10 kDa) and thick (40 nm for 20 kDa) brushes are readily achieved that suppress adsorption from complete serum (10× dilution, exposure for 50 min) by up to 99% on gold (down to 4 ng/cm(2) protein coverage). The brushes outperform oligo(ethylene glycol) monolayers prepared on the same surfaces and analyzed in the same manner. The brush heights are in agreement with calculations based on a simple model similar to the de Gennes "strongly stretched" brush, where the height is proportional to molecular weight. This result has so far generally been considered to be possible only for brushes prepared by grafting-from. Our results are consistent with the theory that the brushes act as kinetic barriers rather than efficient prevention of adsorption at equilibrium. We suggest that the free energy barrier for passing the brush depends on both monomer concentration and thickness. The extraordinary simplicity of the method and good inert properties of the brushes should make our results widely applicable in biointerface science.

Actinomycin D blocks formation of memory of shock-avoidance in goldfish

When 2 micrograms of antinomycin D was injected intracranially into goldfish immediately after a training session, the formation of long-term memory of a shock-avoidance was blocked. The results are discussed in relation to similar findings with acetoxycycloheximide and puromycin in the goldfish and with apparently conflicting results in the mouse.

Purification and characterization of glia maturation factor beta: a growth regulator for neurons and glia

A protein has been isolated from bovine brains by using a modification of the procedure used to purify glia maturation factor. The method consists of ammonium sulfate precipitation, chromatography with DEAE-Sephacel, Sephadex G-75, and hydroxylapatite columns, passage through a heparin-Sepharose column, and finally fractionation by reverse-phase HPLC with a C4 column. The isolated protein reacts strongly with the mouse monoclonal antibody G2-09 and has a molecular weight of approximately 17,000 and an isoelectric point of pH 4.9. The N terminus is blocked, but tryptic digestion releases 28 peptides, 8 of which have been sequenced. The total known residues add up to more than two-thirds of the entire 140-residue protein, estimated from amino acid composition, and show no sequence homology with any known protein. Reversible thermal renaturation greatly enhances its biological activity. The purified protein stimulates differentiation of normal neurons as well as glial cells. It inhibits the proliferation of the N-18 neuroblastoma line and the C6 glioma line while promoting their phenotypic expression. We designate this protein glia maturation factor beta.

Karyopherin-centric control of nuclear pores based on molecular occupancy and kinetic analysis of multivalent binding with FG nucleoporins

Intrinsically disordered Phe-Gly nucleoporins (FG Nups) within nuclear pore complexes exert multivalent interactions with transport receptors (Karyopherins (Kaps)) that orchestrate nucleocytoplasmic transport. Current FG-centric views reason that selective Kap translocation is promoted by alterations in the barrier-like FG Nup conformations. However, the strong binding of Kaps with the FG Nups due to avidity contradicts rapid Kap translocation in vivo. Here, using surface plasmon resonance, we innovate a means to correlate in situ mechanistic (molecular occupancy and conformational changes) with equilibrium (binding affinity) and kinetic (multivalent binding kinetics) aspects of Karyopherinβ1 (Kapβ1) binding to four different FG Nups. A general feature of the FxFG domains of Nup214, Nup62, and Nup153 is their capacity to extend and accommodate large numbers of Kapβ1 molecules at physiological Kapβ1 concentrations. A notable exception is the GLFG domain of Nup98, which forms a partially penetrable cohesive layer. Interestingly, we find that a slowly exchanging Kapβ1 phase forms an integral constituent within the FG Nups that coexists with a fast phase, which dominates transport kinetics due to limited binding with the pre-occupied FG Nups at physiological Kapβ1 concentrations. Altogether, our data reveal an emergent Kap-centric barrier mechanism that may underlie mechanistic and kinetic control in the nuclear pore complex.

Developmental changes in EPSC quantal size and quantal content at a central glutamatergic synapse in rat

1. Developmental changes in amplitude and time course of single-fibre-evoked and spontaneous EPSCs mediated by AMPA and NMDA receptors at the endbulb-bushy cell synapse of rats from 4 to 22 days of age were recorded using whole-cell patch-clamp methods in in vitro slices of cochlear nucleus. 2. The mean conductance of the AMPA component of evoked EPSCs increased by 66 %, while that of the NMDA component decreased by 61 %, for 12- to 18-day-old rats cf. 4- to 11-day-old rats. 3. The mean AMPA spontaneous EPSC conductance increased by 54 %, while mean NMDA spontaneous EPSC conductance decreased by 83 %, for 12- to 22-day-old rats cf. 4- to 11-day-old rats. The mean number of quanta contributing to peak evoked AMPA conductance also increased by 78 % in the older age group, after correction for the asynchrony of evoked quantal release. 4. The decay time constant of spontaneous AMPA EPSCs showed a small decrease in older animals, while the decay time constant of spontaneous NMDA EPSCs was markedly decreased in older animals. The decay time constants of evoked NMDA EPSCs showed a quantitatively similar decrease to that of spontaneous NMDA EPSCs. This suggests that AMPA receptor subunit composition is unlikely to undergo developmental change, while NMDA receptor subunit composition may be substantially altered during synaptic maturation. 5. These data are consistent with a developmentally increased efficacy of AMPA receptor-mediated synaptic transmission at the endbulb-bushy cell synapse, due to an increase in underlying AMPA-mediated quantal size and content during the same period as a transient co-localization of NMDA receptors.

Brain cells in culture: morphological transformation by a protein

One type of elmbryonic rat brain cell having an epithelioid morphology in the monolayer culture can be transformed by brain extract into cells having extensive processes resembling mature astrocytes. The transforming factor is a protein with a molecular weight of 350,000. A partially purified sample showed that it is active at a concentration as low as 1 x 10(-8)M. The transforming actvity is high in adult brains but low in embryonic brains and tumors of the nervous systems.

Molecular cloning and expression of biologically active human glia maturation factor-beta

Glia maturation factor-beta, a protein found in the brains of all vertebrates thus far examined, appears to play a role in the differentiation, maintenance, and regeneration of the nervous system. Using oligonucleotide probes based on the sequences of three tryptic peptides derived from bovine glia maturation factor-beta, we screened a human brainstem cDNA library in lambda gt11. A 0.7-kb clone was isolated, sequenced in its entirety, and found to encode a polypeptide of 142 amino acids which contained regions identical to the three bovine peptides. This polypeptide, human recombinant glia maturation factor-beta, has been expressed in Escherichia coli and found to possess structural characteristics and biological activity indistinguishable from those of the native bovine protein.

GABA mediates presynaptic inhibition at glycinergic synapses in a rat auditory brainstem nucleus

Many inhibitory nerve terminals in the mammalian anteroventral cochlear nucleus (AVCN) contain both glycine and GABA, but the reason for the co-localization of these two inhibitory neurotransmitters in the AVCN is unknown. We have investigated the roles of glycine and GABA at synapses on bushy cells in the rat AVCN, using receptor immunohistochemistry and electrophysiology. Our immunohistochemical results show prominent punctate labelling of postsynaptic clusters of glycine receptors and of the receptor clustering protein gephyrin over the surface of bushy cells. In contrast, weak diffuse membrane immunolabelling of GABAA receptors was observed. Whole-cell recordings from bushy cells in AVCN slices demonstrated that evoked inhibitory postsynaptic currents (IPSCs) were predominantly (81 %) glycinergic, based on the decrease in amplitude of the IPSCs in bicuculline (10 microM). This observation was supported by the effect of strychnine (1 microM), which was to decrease the evoked IPSC (to 10 % of control IPSC amplitude) and to produce a greater than 90 % block of spontaneous miniature IPSCs. These results suggest a minor role for postsynaptic GABAA receptors in bushy cells, despite a high proportion of GABA-containing terminals on these cells. Therefore, a role for metabotropic GABAB receptors was investigated. Activation of GABAB receptors with baclofen revealed a significant attenuation of evoked glycinergic IPSCs. The effect of baclofen was presynaptic, as indicated by a lack of change in the mean amplitude of spontaneous IPSCs. Significantly, the decrease in the amplitude of evoked glycinergic IPSCs observed following repetitive nerve stimulation was reduced in the presence of the GABAB antagonist, CGP 35348. This indicates that synaptically released GABA can activate presynaptic GABAB receptors to reduce transmitter release at glycinergic synapses. Our results suggest specific pre- versus postsynaptic physiological roles for GABA and glycine in the AVCN.

Karyopherins regulate nuclear pore complex barrier and transport function

Kapinos et al. show that nuclear pore complex permeability and cargo release functionalities are concomitantly regulated by karyopherin occupancy and turnover in a systematic continuum. This highlights increasingly important roles for the soluble nucleocytoplasmic transport machinery that depart from established views of the nuclear pore complex selectivity mechanism.

Nucleocytoplasmic transport is sustained by karyopherins (Kaps) and a Ran guanosine triphosphate (RanGTP) gradient that imports nuclear localization signal (NLS)–specific cargoes (NLS-cargoes) into the nucleus. However, how nuclear pore complex (NPC) barrier selectivity, Kap traffic, and NLS-cargo release are systematically linked and simultaneously regulated remains incoherent. In this study, we show that Kapα facilitates Kapβ1 turnover and occupancy at the NPC in a RanGTP-dependent manner that is directly coupled to NLS-cargo release and NPC barrier function. This is underpinned by the binding affinity of Kapβ1 to phenylalanine–glycine nucleoporins (FG Nups), which is comparable with RanGTP·Kapβ1, but stronger for Kapα·Kapβ1. On this basis, RanGTP is ineffective at releasing standalone Kapβ1 from NPCs. Depleting Kapα·Kapβ1 by RanGTP further abrogates NPC barrier function, whereas adding back Kapβ1 rescues it while Kapβ1 turnover softens it. Therefore, the FG Nups are necessary but insufficient for NPC barrier function. We conclude that Kaps constitute integral constituents of the NPC whose barrier, transport, and cargo release functionalities establish a continuum under a mechanism of Kap-centric control.

Deubiquitinase USP10 regulates Notch signaling in the endothelium

Notch signaling is a core patterning module for vascular morphogenesis that codetermines the sprouting behavior of endothelial cells (ECs). Tight quantitative and temporal control of Notch activity is essential for vascular development, yet the details of Notch regulation in ECs are incompletely understood. We found that ubiquitin-specific peptidase 10 (USP10) interacted with the NOTCH1 intracellular domain (NICD1) to slow the ubiquitin-dependent turnover of this short-lived form of the activated NOTCH1 receptor. Accordingly, inactivation of USP10 reduced NICD1 abundance and stability and diminished Notch-induced target gene expression in ECs. In mice, the loss of endothelial Usp10 increased vessel sprouting and partially restored the patterning defects caused by ectopic expression of NICD1. Thus, USP10 functions as an NICD1 deubiquitinase that fine-tunes endothelial Notch responses during angiogenic sprouting.