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The looming antibiotic crisis has prompted the development of new strategies towards fighting infection. Traditional antibiotics target bacterial processes essential for viability, whereas proposed antivirulence approaches rely on the inhibition of factors that are required only for the initiation and propagation of infection within a host. Although antivirulence compounds have yet to prove their efficacy in the clinic, bacterial signal peptidase I (SPase) represents an attractive target in that SPase inhibitors exhibit broad-spectrum antibiotic activity, but even at sub-MIC doses also impair the secretion of essential virulence factors. The potential consequences of SPase inhibition on bacterial virulence have not been thoroughly examined, and are explored within this review. In addition, we review growing evidence that SPase has relevant biological functions outside of mediating secretion, and discuss how the inhibition of these functions may be clinically significant. [ABSTRACT FROM AUTHOR]

The general secretory pathway has long been regarded as a potential antibiotic drug target. In particular, bacterial type I signal peptidase (SPase) is emerging as a strong candidate for therapeutic use. In this review, we focus on the information gained from the use of SPase inhibitors as probes of prokaryote biology. A thorough understanding of the consequences of SPase inhibition and the mechanisms of resistance that arise are essential to the success of SPase as an antibiotic target. In addition to the role of SPase in processing secreted proteins, the use of SPase inhibitors has elucidated a previously unknown function for SPase in regulating cleavage events of membrane proteins. [ABSTRACT FROM AUTHOR]

The Space Physics Archive Search and Extract (SPASE) project is an international collaboration among Heliophysics (solar and space physics) groups concerned with data acquisition and archiving. The SPASE group has simplified the search for data through the development of the SPASE Data model as a common method to describe data sets in the archives. The data model is an XML-based schema and is now in operational use. The use is expanding, but there are still other groups who could benefit from adopting SPASE. We discuss the present state of SPASE usage and how we foresee development in the future.

The Space Physics Archive Search and Extract (SPASE) project has developed an information model for interoperable access and retrieval of data within the Heliophysics (also known as space and solar physics) science community. The diversity of science data archives within this community has led to the establishment of many virtual observatories to coordinate the data pathways within Heliophysics subdisciplines, such as magnetospheres, waves, radiation belts, etc. The SPASE information model provides a semantic layer and common language for data descriptions so that searches might be made across the whole of the heliophysics data environment, especially through the virtual observatories.

The Space Physics Archive Search and Extract (SPASE) project is an international collaboration among Heliophysics (solar and space physics) groups concerned with data acquisition and archiving. The SPASE group has simplified the search for data through the development of the SPASE Data model as a common method to describe data sets in the archives. The data model is an XML-based schema and is now in operational use. The use is expanding, but there are still other groups who could benefit from adopting SPASE. We discuss the present state of SPASE usage and how we foresee development in the future. [ABSTRACT FROM AUTHOR]

SPASE—for Space Physics Archive Search and Extract—is a group with a charter to promote collaboration and sharing of data for the Space Plasma Physics community. A major activity is the definition of the SPASE Data Model which defines the metadata necessary to describe resources in the broader heliophysics data environment. The SPASE Data Model is primarily a controlled vocabulary with hierarchical relationships and with the ability to form associations between described resources. It is the result of many years of effort by an international collaboration (see ) to unify and improve on existing Space and Solar Physics data models. The genesis of the SPASE group can be traced to 1998 when a small group of individuals saw a need for a data model. Today SPASE has a large international participation from many of the major space research organizations. The design of the data model is based on a set of principles derived from evaluation of the existing heliophysics data environment. The development guidelines for the data model are consistent with ISO-2788 (expanded in ANSI/NISO Z39.19) and the administration for the data model is comparable to that described in the ISO standards ISO-11179 and ISO-20943. Since the release of version 1.0 of the data model in 2005, the model has undergone a series of evolutions. SPASE released version 2.0 of its data model in April 2009. This version presents a significant change from the previous release. It includes the capability to describe a wider range of data products and to describe expert annotations which can be associated with a resource. Additional improvements include an enhanced capability to describe resource associations and a more unified approach to describing data products. Version 2.0 of the SPASE Data Model provides a solid foundation for continued integration of worldwide research activities and the open sharing of data. [ABSTRACT FROM AUTHOR]

Information is shared within organizations and between organizations at an ever increasing rate. One system design that enables sharing in a distributed environment is a Virtual Observatory. A Virtual Observatory is built with clearly specified and standardized components. One essential component is a data model for the exchange of metadata. Well designed data models are compatible with the tenets of the ISO-11179 and ISO-20943 standards for metadata registries. Another essential component is the specification for persistent universal identifiers which are used to reference resources provided through the system. Identifiers are used both to link harvested information back to the original resource description and by services to retrieve a resource. Harvested information is maintained in a registry. To harvest information from a set of metadata it is necessary to understand the schema of the metadata. We propose an approach to the formation of universal identifiers which enables one to clearly discern the schema of the source metadata. A primary registry containing a broad set of base information exists in every Virtual Observatory. Specialized Task Oriented Registries (TOR) are typically derived from the primary registry. The schema in a TOR is often flat and items in the TOR can be managed in a similar manner to that prescribed in ISO-11179. The need for interoperability within a data environment and between data environments leads to the identification of broad-based, common attributes we call “Rosetta Attributes” which will enable general cross domain searches. Access to metadata is the final component of a Virtual Observatory. Access is provided by a registry service. A specification for a minimal registry service is presented. [ABSTRACT FROM AUTHOR]

As soon as the first data became available online over the Internet, it was obvious that different sites holding related datasets should appear to the end user as a single data system, even if the data itself is stored at multiple locations. To achieve this objective in the context of continuing parallel development of multiple data centres, in 2003 several actors in the realm of space plasmas created the international consortium Space Physics Archive Search and Extract (SPASE). Since 2005 US participation in SPASE has been supported by NASA, and early in 2006 NASA funded five new Virtual Observatories to cater for different aspects of solar system plasma science. This paper outlines the current status of the SPASE effort, the opportunities it offers, its specificities with respect to other parts of the astronomical virtual observatory, and the possibilities it offers for space weather. [ABSTRACT FROM AUTHOR]

Abstract: The signal hypothesis suggests that proteins contain information within their amino acid sequences for protein targeting to the membrane. These distinct targeting sequences are cleaved by specific enzymes known as signal peptidases. There are various type of signal peptidases known such as type I, type II, and type IV. Type I signal peptidases are indispensable enzymes, which catalyze the cleavage of the amino-terminal signal-peptide sequences from preproteins, which are translocated across biological membranes. These enzymes belong to a novel group of serine proteases, which generally utilize a Ser-Lys or Ser-His catalytic dyad instead of the prototypical Ser-His-Asp triad. Despite having no distinct consensus sequence other than a commonly found ‘Ala-X-Ala’ motif preceding the cleavage site, signal sequences are recognized by type I signal peptidase with high fidelity. Type I signal peptidases have been found in bacteria, archaea, fungi, plants, and animals. In this review, I present an overview of bacterial type I signal peptidases and describe some of their properties in detail. [Copyright &y& Elsevier]

SPase is a cysteine protease isolated from an African green monkey kidney cell line, CV-1, and has selective cleavage activity toward transcription factor SP-1 and retinoblastoma susceptibility gene product RB. In this study, a cDNA encoding SPase was cloned from a cDNA library prepared from CV-1 cells. The cDNA clone encodes 333 amino acids and is 96.5% identical to human cathepsin L at the nucleotide and amino acid sequence levels. SPase appears to be translated as a preproenzyme based on the comparison between the deduced amino acid sequence and the N-terminal sequence of the purified enzyme. Northern blot analysis exhibited the considerably higher expression of SPase in CV-1 cells compared with COS-1 cells, showing a good correlation with enzymatic activity in these cell lines. Bacterially expressed SPase protein exhibited proteolytic activity toward SP-1 and RB proteins. These observations suggest that SPase is a monkey cathepsin L orthologue. [ABSTRACT FROM AUTHOR]

Co-translational protein targeting to the endoplasmic reticulum (ER), represents an evolutionary-conserved mechanism to target proteins into the secretory pathway. In this targeting pathway proteins possessing signal sequences are recognised at the ribosome by the signal recognition particle while they are still undergoing synthesis. This triggers their delivery to the ER protein translocation channel, where they are directly translocated into the ER. Here we review the current understanding of this translocation pathway and how molecular details obtained in the related bacterial system have provided insight into the mechanism of targeting and translocation. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum., (Copyright © 2013. Published by Elsevier B.V.)