Data-intensive research depends on tools that manage multi-dimensional, heterogeneous data sets. We have built OME Remote Objects (OMERO), a software platform that enables access to and use of a wide range of biological data. OMERO uses a server-based middleware application to provide a unified interface for images, matrices, and tables. OMERO’s design and flexibility have enabled its use for light microscopy, high content screening, electron microscopy, and even non-image genotype data. OMERO is open source software and available at http://openmicroscopy.org.

Biofilms represent the predominant mode of microbial growth in the natural environment. Bacillus subtilis is a ubiquitous Gram-positive soil bacterium that functions as an effective plant growth-promoting agent. The biofilm matrix is composed of an exopolysaccharide and an amyloid fiber-forming protein, TasA, and assembles with the aid of a small secreted protein, BslA. Here we show that natively synthesized and secreted BslA forms surface layers around the biofilm. Biophysical analysis demonstrates that BslA can self-assemble at interfaces, forming an elastic film. Molecular function is revealed from analysis of the crystal structure of BslA, which consists of an Ig-type fold with the addition of an unusual, extremely hydrophobic “cap” region. A combination of in vivo biofilm formation and in vitro biophysical analysis demonstrates that the central hydrophobic residues of the cap are essential to allow a hydrophobic, nonwetting biofilm to form as they control the surface activity of the BslA protein. The hydrophobic cap exhibits physiochemical properties remarkably similar to the hydrophobic surface found in fungal hydrophobins; thus, BslA is a structurally defined bacterial hydrophobin. We suggest that biofilms formed by other species of bacteria may have evolved similar mechanisms to provide protection to the resident bacterial community.

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Ablation guided by automated detection of CFAE proved feasible, and was associated with a high AF termination rate in paroxysmal, but not persistent AF. As an adjunct to conventional techniques, it was associated with excellent long-term single procedure outcomes in both groups. Criteria for identifying optimal CFAE sites for ablation, and selection of patients most likely to benefit, require additional study.

SummaryThe Type VI secretion system (T6SS) is a bacterial nanomachine that fires toxic proteins into target cells. Deployment of the T6SS represents an efficient and widespread means by which bacteria attack competitors or interact with host organisms and may be triggered by contact from an attacking neighbor cell as a defensive strategy. Here, we use the opportunist pathogen Serratia marcescens and functional fluorescent fusions of key components of the T6SS to observe different subassemblies of the machinery simultaneously and on multiple timescales in vivo. We report that the localization and dynamic behavior of each of the components examined is distinct, revealing a multi-stage and dynamic assembly process for the T6SS machinery. We also show that the T6SS can assemble and fire without needing a cell contact trigger, defining an aggressive strategy that broadens target range and suggesting that activation of the T6SS is tailored to survival in specific niches.

Mitotic entry and progression require the activation of several mitotic kinases and the proper regulation and localization of several phosphatases. The activity and localization of each of these enzymes is tightly controlled through a series of specific activators, inhibitors and regulatory subunits. Two proteins, Ensa and Arpp-19, were recently identified as specific inhibitors of PP2A-B55 and are critical for allowing full activity of Cdk1/cyclin B and entry into mitosis. Here we show that Bod1, a protein required for proper chromosome alignment at mitosis, shares sequence similarity with Ensa and Arpp-19 and specifically inhibits the kinetochore-associated PP2A-B56 holoenzyme. PP2A-B56 regulates the stability of kinetochore-microtubule attachments by dephosphorylating several kinetochore proteins. Loss of Bod1 changes the balance of phosphorylation at kinetochores, causing defects in kinetochore function. Bod1, Ensa and Arpp-19 define a family of specific PP2A inhibitors that regulate specific PP2A holoenzymes at distinct locations and points in the cell cycle.

PTEN tumor suppressor gene failure in ras Ha -activated skin carcinogenesis was investigated by mating exon 5 floxed-PTEN (#5PTEN) mice to HK1.ras mice that expressed a RU486-inducible cre recombinase (K14.creP). PTEN inactivation in K14.cre/PTEN flx/flx keratinocytes resulted in epidermal hyperplasia/hyperkeratosis and novel 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted papillomas, whereas HK1.ras/K14.cre/PTEN flx/flx cohorts displayed a rapid onset of papillomatogenesis due to a synergism of increased AKT activity and extracellular signal-regulated kinase (ERK) elevation. High 5-bromo-4-deoxyuridine labeling in #5PTEN papillomas showed that a second promotion mechanism centered on failures in cell cycle control. Elevated cyclin D1 was associated with both HK1.ras/ERK-and #5PTEN-mediated AKT signaling, whereas cyclin E2 overexpression seemed dependent on PTEN loss. Spontaneous HK1.ras/ #5PTEN malignant conversion was rare, whereas TPA promotion resulted in conversion with high frequency. On comparison with all previous HK1.ras carcinomas, such TPAinduced carcinomas expressed atypical retention of keratin K1 and lack of K13, a unique marker profile exhibited by TPAinduced K14.cre/PTEN flx/flx papillomas that also lacked endogenous c-ras Ha activation. Moreover, in all PTEN-null tumors, levels of ras Ha -associated total ERK protein became reduced, whereas phosphorylated ERK and cyclin D1 were lowered in late-stage papillomas returning to elevated levels, alongside increased cyclin E2 expression, in TPA-derived carcinomas. Thus, during early papillomatogenesis, PTEN loss promotes rasHa initiation via elevation of AKT activity and synergistic failures in cyclin regulation. However, in progression, reduced ras Ha -associated ERK protein and activity, increased #5PTEN-associated cyclin E2 expression, and unique K1/K13 profiles following TPA treatment suggest that PTEN loss, rather than ras Ha activation, gives rise to a population of cells with greater malignant potential. (Cancer Res 2006; 66(3): 1302-12)