Cdc42 promotes transendothelial migration of cancer cells through β1 integrin.

Cancer cells interact with endothelial cells during the process of metastatic spreading. Here, we use a small interfering RNA screen targeting Rho GTPases in cancer cells to identify Cdc42 as a critical regulator of cancer cell-endothelial cell interactions and transendothelial migration. We find that Cdc42 regulates β1 integrin expression at the transcriptional level via the transcription factor serum response factor (SRF). β1 integrin is the main target for Cdc42-mediating interaction of cancer cells with endothelial cells and the underlying extracellular matrix, as exogenous β1 integrin expression was sufficient to rescue the Cdc42-silencing phenotype. We show that Cdc42 was required in vivo for cancer cell spreading and protrusion extension along blood vessels and retention in the lungs. Interestingly, transient Cdc42 depletion was sufficient to decrease experimental lung metastases, which suggests that its role in endothelial attachment is important for metastasis. By identifying β1 integrin as a transcriptional target of Cdc42, our results provide new insight into Cdc42 function

Stochastic models and dynamic measures for the characterization of bistable circuits

During the last few years, a great deal of interest has risen concerning the applications of stochastic methods to several biochemical and biological phenomena. Phenomena like gene expression, cellular memory, bet-hedging strategy in bacterial growth and many others, cannot be described by continuous stochastic models due to their intrinsic discreteness and randomness. In this thesis I have used the Chemical Master Equation (CME) technique to modelize some feedback cycles and analyzing their properties, including experimental data. In the first part of this work, the effect of stochastic stability is discussed on a toy model of the genetic switch that triggers the cellular division, which malfunctioning is known to be one of the hallmarks of cancer. The second system I have worked on is the so-called futile cycle, a closed cycle of two enzymatic reactions that adds and removes a chemical compound, called phosphate group, to a specific substrate. I have thus investigated how adding noise to the enzyme (that is usually in the order of few hundred molecules) modifies the probability of observing a specific number of phosphorylated substrate molecules, and confirmed theoretical predictions with numerical simulations. In the third part the results of the study of a chain of multiple phosphorylation-dephosphorylation cycles will be presented. We will discuss an approximation method for the exact solution in the bidimensional case and the relationship that this method has with the thermodynamic properties of the system, which is an open system far from equilibrium.In the last section the agreement between the theoretical prediction of the total protein quantity in a mouse cells population and the observed quantity will be shown, measured via fluorescence microscopy

Insect pathogens as biological control agents: back to the future

The development and use of entomopathogens as classical, conservation and augmentative biological control agents have included a number of successes and some setbacks in the past 15 years. In this forum paper we present current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance. Insect pathogenic viruses are a fruitful source of MCAs, particularly for the control of lepidopteran pests. Most research is focused on the baculoviruses, important pathogens of some globally important pests for which control has become difficult due to either pesticide resistance or pressure to reduce pesticide residues. Baculoviruses are accepted as safe, readily mass produced, highly pathogenic and easily formulated and applied control agents. New baculovirus products are appearing in many countries and gaining an increased market share. However, the absence of a practical in vitro mass production system, generally higher production costs, limited post application persistence, slow rate of kill and high host specificity currently contribute to restricted use in pest control. Overcoming these limitations are key research areas for which progress could open up use of insect viruses to much larger markets. A small number of entomopathogenic bacteria have been commercially developed for control of insect pests. These include several Bacillus thuringiensis sub-species, Lysinibacillus (Bacillus) sphaericus, Paenibacillus spp. and Serratia entomophila. B. thuringiensis sub-species kurstaki is the most widely used for control of pest insects of crops and forests, and B. thuringiensis sub-species israelensis and L. sphaericus are the primary pathogens used for medically important pests including dipteran vectors,. These pathogens combine the advantages of chemical pesticides and microbial control agents (MCAs): they are fast acting, easy to produce at a relatively low cost, easy to formulate, have a long shelf life and allow delivery using conventional application equipment and systemics (i.e. in transgenic plants). Unlike broad spectrum chemical pesticides, B. thuringiensis toxins are selective and negative environmental impact is very limited. Of the several commercially produced MCAs, B. thuringiensis (Bt) has more than 50% of market share. Extensive research, particularly on the molecular mode of action of Bt toxins, has been conducted over the past two decades. The Bt genes used in insect-resistant transgenic crops belong to the Cry and vegetative insecticidal protein families of toxins. Bt has been highly efficacious in pest management of corn and cotton, drastically reducing the amount of broad spectrum chemical insecticides used while being safe for consumers and non-target organisms. Despite successes, the adoption of Bt crops has not been without controversy. Although there is a lack of scientific evidence regarding their detrimental effects, this controversy has created the widespread perception in some quarters that Bt crops are dangerous for the environment. In addition to discovery of more efficacious isolates and toxins, an increase in the use of Bt products and transgenes will rely on innovations in formulation, better delivery systems and ultimately, wider public acceptance of transgenic plants expressing insect-specific Bt toxins. Fungi are ubiquitous natural entomopathogens that often cause epizootics in host insects and possess many desirable traits that favor their development as MCAs. Presently, commercialized microbial pesticides based on entomopathogenic fungi largely occupy niche markets. A variety of molecular tools and technologies have recently allowed reclassification of numerous species based on phylogeny, as well as matching anamorphs (asexual forms) and teleomorphs (sexual forms) of several entomopathogenic taxa in the Phylum Ascomycota. Although these fungi have been traditionally regarded exclusively as pathogens of arthropods, recent studies have demonstrated that they occupy a great diversity of ecological niches. Entomopathogenic fungi are now known to be plant endophytes, plant disease antagonists, rhizosphere colonizers, and plant growth promoters. These newly understood attributes provide possibilities to use fungi in multiple roles. In addition to arthropod pest control, some fungal species could simultaneously suppress plant pathogens and plant parasitic nematodes as well as promote plant growth. A greater understanding of fungal ecology is needed to define their roles in nature and evaluate their limitations in biological control. More efficient mass production, formulation and delivery systems must be devised to supply an ever increasing market. More testing under field conditions is required to identify effects of biotic and abiotic factors on efficacy and persistence. Lastly, greater attention must be paid to their use within integrated pest management programs; in particular, strategies that incorporate fungi in combination with arthropod predators and parasitoids need to be defined to ensure compatibility and maximize efficacy. Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are potent MCAs. Substantial progress in research and application of EPNs has been made in the past decade. The number of target pests shown to be susceptible to EPNs has continued to increase. Advancements in this regard primarily have been made in soil habitats where EPNs are shielded from environmental extremes, but progress has also been made in use of nematodes in above-ground habitats owing to the development of improved protective formulations. Progress has also resulted from advancements in nematode production technology using both in vivo and in vitro systems; novel application methods such as distribution of infected host cadavers; and nematode strain improvement via enhancement and stabilization of beneficial traits. Innovative research has also yielded insights into the fundamentals of EPN biology including major advances in genomics, nematode-bacterial symbiont interactions, ecological relationships, and foraging behavior. Additional research is needed to leverage these basic findings toward direct improvements in microbial control

Corporate Incubators: Industrial R&D and What Universities can Learn from them

The explosive growth of incubation has seen a concurrent and significant increase in research on and knowledge of the incubation phenomenon. However, instead of comprehensively differentiating between non-profit and for-profit incubators, research has described a whole array of partly overlapping archetypes, thus missing out on important aspects. This article first offers two arguments validating a framework of what non-profit university incubators can learn from for-profit corporate incubators before presenting the framework itself. While corporate incubators are for-profit organizations with which to enhance a corporation’s technology development, university incubators try to leverage technological insights from the university in a similar manner. In accordance with their respective missions, organizational structures, incubator processes and resource flows, it is possible to transfer lessons learned from two corporate incubator archetypes—the fast-profit incubator and leveraging incubator—to the world of university incubator. Our empirical findings are based on in-depth case studies of 25 companies through 52 semi-structured interviews with managers of corporate incubators of large technology-intensive corporations in Europe and the U.S., two EU incubator benchmarking surveys and five interviews with the heads of technology transfer offices of two top technology universities. Copyright Springer Science+Business Media, LLC 2006American and European Incubators, industrial R & D, industry spin-offs, venturing, innovation, O31, O32,

TOWARDS A RESOURCE-BASED VIEW OF CORPORATE INCUBATORS

Corporate incubators for technology development are a recent phenomenon whose functioning and implications are not yet well understood. The resource-based view can offer an explanatory model on how corporate incubators function as specialised corporate units that hatch new businesses. While tangible resources, such as the financial, physical and even explicit knowledge flow, are all visible, and therefore easy to measure, intangible resources such as tacit knowledge and branding flow are harder to detect and localise. Managing the resource flow requires the initial allocation of resources to the corporate incubator during its set-up as well as a continuous resource flow to the technology venture and, during the harvest phase, also from it. Two levels of analysis need to be distinguished: (1) the resource flow between the corporate incubator and the technology venture and (2) the resource flow interface between the corporate incubator and the technology venture. Our empirical findings are based on two phases: First, in-depth case studies of 22 companies through 47 semi-structured interviews that were conducted with managers of large technology-intensive corporations' corporate incubators in Europe and the U.S., and second, an analysis of the European Commission's benchmarking survey of 77 incubators.Innovation process, corporate incubators, resource based view, venturing

Prospect First – Dig Then! Investigations of Mining and Metallurgical Features in Kosovo

Inspired by the Römisch-Germanische Kommission (RGK) in Frankfurt and the Archaeological Institute of Kosovo, the first mining  archaeological/archaeometallurgical surveys were conducted in Kosovo in 2009-2011 by the Deutsches Bergbau-Museum Bochum (DBM) / German Mining Museum Bochum. We conducted the surveys mainly in cooperation with the Archaeological Institute of  Kosovo. After the approval of two project phases by the DFG in 2012, five field campaigns were carried out (2013-15, 2017/18). The  mining archaeologically oriented excavations were also carried out based on extensive prospection work by magnetometer  prospection, geoelectric and pedological drillings. Initially used in different areas – magnetometer prospection and “Pürckhauer”  drillings in settlement areas and on smelting sites, geoelectric investigations in mining areas - it became more and more clear that the  combination of the methods would be a promising approach and added value for the clarification of features, also and especially in mining areas. The specific combination of the methods makes it possible, particularly in the case of extensive fields of mining  depressions such as those found in the Shashkoc/Janjevo area, to get ideas of their size and, above all, the shape of the shaft  entrances, not just the depth, as initially planned. The shape of the mouth holes may be a very important indication of the age of the  shafts, which in turn influences the planned excavations. Thus, unnecessary excavations can be avoided. Therefore, in the past two  campaigns a whole series of mining depressions were investigated in this way. In order to evaluate and compare the measurement  results, targeted excavations were then carried out in the upper areas of the shafts. Although there are restrictive conditions such as different soil types, magnetic and electric disturbances and similar factors that may impede the measurement results, the combination of methods has provided considerable  benefit and created a systematic working basis, future investigation can build on.&nbsp

Business models for digital sustainability : Framework, microfoundations of value capture, and empirical evidence from 130 smart city services

The emerging research stream on digital sustainability examines how digital technologies enable the creation of environmental and social value. The need to finance the creation of such value calls for a business model perspective that combines value creation and value capture. To extend the digital sustainability literature in this regard, we adopt a microfoundations perspective and argue that the configuration of value creation influences the decision of users to pay for a value proposition or not, which in turn affects organizational value capture. Applying a crisp-set qualitative comparative analysis to 130 smart city initiatives in Switzerland, we develop a three-dimensional framework of business models for digital sustainability. The framework comprises 12 theoretically possible business model types, representing distinct business model configurations. We contribute to the digital sustainability and the microfoundations literatures by analyzing, explaining, and classifying the diversity of digitally enabled business models in the context of smart cities.Validerad;2023;Nivå 2;2023-04-14 (joosat);Funder: Swiss National Science Foundation (project number 407740_187381); Research Council of NorwayLicens fulltext: CC BY License</p

The Sushi domains of GABAB receptors function as axonal targeting signals

GABA(B) receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the brain. Two receptor subtypes, GABA(B(1a,2)) and GABA(B(1b,2)), are formed by the assembly of GABA(B1a) and GABA(B1b) subunits with GABA(B2) subunits. The GABA(B1b) subunit is a shorter isoform of the GABA(B1a) subunit lacking two N-terminal protein interaction motifs, the sushi domains. Selectively GABA(B1a) protein traffics into the axons of glutamatergic neurons, whereas both the GABA(B1a) and GABA(B1b) proteins traffic into the dendrites. The mechanism(s) and targeting signal(s) responsible for the selective trafficking of GABA(B1a) protein into axons are unknown. Here, we provide evidence that the sushi domains are axonal targeting signals that redirect GABA(B1a) protein from its default dendritic localization to axons. Specifically, we show that mutations in the sushi domains preventing protein interactions preclude axonal localization of GABA(B1a). When fused to CD8alpha, the sushi domains polarize this uniformly distributed protein to axons. Likewise, when fused to mGluR1a the sushi domains redirect this somatodendritic protein to axons, showing that the sushi domains can override dendritic targeting information in a heterologous protein. Cell surface expression of the sushi domains is not required for axonal localization of GABA(B1a). Altogether, our findings are consistent with the sushi domains functioning as axonal targeting signals by interacting with axonally bound proteins along intracellular sorting pathways. Our data provide a mechanistic explanation for the selective trafficking of GABA(B(1a,2)) receptors into axons while at the same time identifying a well defined axonal delivery module that can be used as an experimental tool

The RXR-type endoplasmic reticulum-retention/retrieval signal of GABAB1 requires distant spacing from the membrane to function

Functional gamma-aminobutyric acid type B (GABA(B)) receptors are normally only observed upon coexpression of GABA(B1) with GABA(B2) subunits. A C-terminal arginine-based endoplasmic reticulum (ER) retention/retrieval signal, RSRR, prevents escape of unassembled GABA(B1) subunits from the ER and restricts surface expression to correctly assembled heteromeric receptors. The RSRR signal in GABA(B1) is proposed to be shielded by C-terminal coiled-coil interaction of the GABA(B1) with the GABA(B2) subunit. Here, we investigated whether the RSRR motif in GABA(B1) remains functional when grafted to ectopic sites. We found that the RSRR signal in GABA(B1) is inactive in any of the three intracellular loops but remains functional when moved within the distal zone of the C-terminal tail. C-terminal deletions that position the RSRR signal closer to the plasma membrane drastically reduce its effectiveness, supporting that proximity to the membrane restricts access to the RSRR motif. Functional ectopic RSRR signals in GABA(B1) are efficiently inactivated by the GABA(B2) subunit in the absence of coiled-coil dimerization, supporting that coiled-coil interaction is not critical for release of the receptor complex from the ER. The data are consistent with a model in which removal of RSRR from its active zone rather than its direct shielding by coiled-coil dimerization triggers forward trafficking. Because arginine-based intracellular retention signals of the type RXR, where X represents any amino acid, are used to regulate assembly and surface transport of several multimeric complexes, such a mechanism may apply to other proteins as well