The response of derepressed cells of Schizosaccharomyces pombe to the addition of glucose included a marked and reversible activation of neutral trehalase that was not produced in repressed cells. The protein synthesis inhibitor cycloheximide, the protonophore 2,4dinitrophenol or the uncoupler sodium azide also enhanced trehalase activity in derepressed cells provided glucose was present in the incubation assays. However, only 2,4=dinitrophenol or cycloheximide was able to induce trehalase activation in repressed cells. Stimulation of trehalase by these compounds was preceded in all cases by a rapid increase in adenosine 3'-5'-cyclic monophosphate (CAMP) content. Since exogenous CAMP can activate trehalase both in repressed and derepressed growing cells, the results provide evidence for the existence of an induced CAMP signalling pathway in the fission yeast with several entries for trehalase activation. The correlation between CAMP increase and trehalase activation was not maintained when the enzyme was heat-shock-activated, supporting the concept that trehalase activity can be also enhanced in cells by another mechanism in which CAMP does not act as second messenger.

Please cite this article in press as: J.L. Hernández-Ramos et al., SAFIR: Secure access framework for IoT-enabled services on smart buildings, J. Comput. Syst. Sci. (2015), http://dx. Highlights• We develop a SAFIR based on City Explorer, which has been developed previously.• SAFI extends City Explorer functionalities with discovery and security modules.• We evaluate the discovery and authorization mechanisms.• Suitability of our platform for smart and secure buildings has been validated. AbstractRecent advances on ubiquitous computing and communication technologies are enabling a seamless integration of smart devices in the Internet infrastructure, promoting a new generation of innovative and valuable services for people. Nevertheless, the potential of this resulting ecosystem may be threatened if security and privacy concerns are not properly addressed. In this work, we propose an ARM-compliant IoT security framework and its application on smart buildings scenarios, integrating contextual data as fundamental component in order to drive the building management and security behavior of indoor services accordingly. This framework is instantiated on a holistic platform called City explorer, which is extended with discovery and security mechanisms. Such platform has been validated in a reference smart building, where reasonable results of energy savings, services discovery and authorization are achieved.

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Derepressed cells of Candida uti/is suspended in buffer exhibited both a transient CAMP-mediated signal and a marked activation of cytoplasmic trehalase when supplemented with glucose. Nitrogen sources or protein synthesis inhibitors, as well as protonophores or uncouplers, were also able to cause trehalase stimulation in derepressed cells even in the absence of the sugar. The increase in trehalase activity caused by nitrogen sources or protein synthesis inhibitors was not accompanied by changes in CAMP levels. Moreover, acridine orange inhibited both the CAMP signal and the glucoseinduced activation of trehalase without affecting the increase in trehalase activity caused by nitrogen sources or protein synthesis inhibitors. These results suggest that CAMP is not involved as second messenger in the signal for trehalase stimulation induced by the latter compounds. By contrast, the addition of glucose to repressed cells suspended in buffer failed to cause the CAMP-mediated glucose signal and sugar-induced trehalase activation. No significant changes in either trehalase activity or CAMP concentration were observed upon addition to these cells of asparagine, cycloheximide, anisomycin or other agents, including protonophores and uncouplers. However, heat treatment of repressed cultures resulted in a moderate increase in trehalase activity with negligible change in CAMP levels, whereas such an effect was not observed in derepressed cultures. The thermally induced increase in trehalase activity was dependent on de now0 protein synthesis and required the presence of glucose. Since in all cases the enzyme activated in wiwo was deactivated in vitm by phosphatase our data support the idea that in C. utilis there are at least three independent mechanisms to increase trehalase activity, involving different, but overlapping, phosphorylation pathways.

The rise in cAMP level that follows the addition of glucose or 2,4-dinitrophenol (DNP) to stationary-phase cells of Saccharomyces cerevisiae was accompanied by a marked activation of trehalase (3-fold increase) and a concomitant deactivation of trehalose-6 phosphate synthase (50% of the basal levels). In glucose-grown exponential cells, which are deficient in glucose-induced cAMP signalling, the addition of glucose also prompted a decrease in trehalose-6 phosphate synthase, but had no effect on trehalase activity. Mutants defective in the RAS-adenylate cyclase pathway (ras1 ras2 bcy1 strain), as well as mutants containing greatly reduced protein kinase activity either cAMP-dependent (tpkw1 BCY1 strains) or cAMP-independent (tpk1w1 bcy1 strains), were unable to show glucose- or DNP-induced trehalase activation but still displayed a clear decrease in trehalose-6 phosphate synthase activity upon addition of these compounds. These data suggest that the activity of trehalose-6 phosphate synthase, as opposed to that of trehalase, is not controlled by the cAMP signalling pathway "in vivo". Trehalose-6 phosphate synthase was competitively inhibited by glucose (Ki = 15 mM) and resulted unaffected by ATP in assays performed "in vitro".