Sprouty (SPRY) appears to act as a tumor suppressor in cancer, whereas we demonstrated that SPRY2 functions as a putative oncogene in colorectal cancer (CRC) (Oncogene, 2010, 29: 5241-5253). We ...investigated the mechanisms by which SPRY regulates epithelial-mesenchymal transition (EMT) in CRC. SPRY1 and SPRY2 mRNA transcripts were significantly upregulated in human CRC. Suppression of SPRY2 repressed AKT2 and EMT-inducing transcription factors and significantly increased E-cadherin expression. Concurrent downregulation of SPRY1 and SPRY2 also increased E-cadherin and suppressed mesenchymal markers in colon cancer cells. An inverse expression pattern between AKT2 and E-cadherin was established in a human CRC tissue microarray. SPRY2 negatively regulated miR-194-5p that interacts with AKT2 3' untranslated region. Mir-194 mimics increased E-cadherin expression and suppressed cancer cell migration and invasion. By confocal microscopy, we demonstrated redistribution of E-cadherin to plasma membrane in colon cancer cells transfected with miR-194. Spry1(-/-) and Spry2(-/-) double mutant mouse embryonic fibroblasts exhibited decreased cell migration while acquiring several epithelial markers. In CRC, SPRY drive EMT and may serve as a biomarker of poor prognosis.
Plakoglobin, a member of the armadillo family of proteins, is a component of intercellular adhesive junctions. The central domain of plakoglobin comprises a highly conserved series of armadillo ...repeats that facilitate its association with either desmosomal or classic cadherins, or with cytosolic proteins such as the tumor suppressor gene product adenomatous polyposis coli. Sequences in the N- and C-terminal domains of plakoglobin are less highly conserved, and their possible roles in regulating plakoglobin's subcellular distribution and junction assembly are still unclear. Here we have examined the role of plakoglobin end domains by stably expressing constructs lacking the N and/or C terminus of plakoglobin in A-431 cells. Our results demonstrate that myc-tagged plakoglobin lacking either end domain is still able to associate with the desmosomal cadherin desmoglein and incorporate into desmosomes. In cell lines that express an N-terminal truncation of plakoglobin, an increase in the cytosolic pool of en-dogenous and ectopic plakoglobin was observed that may reflect an increase in the stability of the protein. Deletion of the N terminus did not have a dramatic effect on the structure of desmosomes in these cells. On the other hand, striking alterations in desmosome morphology were observed in cells expressing C-terminal truncations of plakoglobin. In these cell lines, ectopic plakoglobin incorporated into desmosomes, and extremely long junctions or groups of tandemly linked desmosomes which remained well attached to keratin intermediate filaments, were observed. Together, these results suggest that plakoglobin end domains play a role in regulating its subcellular distribution, and that the presence of the C terminus limits the size of desmosomes, perhaps through regulating protein-protein interactions required for assembly of the desmosomal plaque.
We present a technique for automatically deriving test data generators from a given executable predicate representing the set of values we are interested in generating. The distribution of these ...generators is uniform over values of a given size. To make the generation efficient, we rely on laziness of the predicate, allowing us to prune the space of values quickly. In contrast, implementing test data generators by hand is labour intensive and error prone. Moreover, handwritten generators often have an unpredictable distribution of values, risking that some values are arbitrarily underrepresented. We also present a variation of the technique that has better performance, but where the distribution is skewed in a limited, albeit predictable way. Experimental evaluation of the techniques shows that the automatically derived generators are much easier to define than handwritten ones, and their performance, while lower, is adequate for some realistic applications.
The desmosome is a highly organized plasma membrane domain that couples intermediate filaments to the plasma membrane at regions of cell-cell adhesion. Desmosomes contain two classes of cadherins, ...desmogleins, and desmocollins, that bind to the cytoplasmic protein plakoglobin. Desmoplakin is a desmosomal component that plays a critical role in linking intermediate filament networks to the desmosomal plaque, and the amino-terminal domain of desmoplakin targets desmoplakin to the desmosome. However, the desmosomal protein(s) that bind the amino-terminal domain of desmoplakin have not been identified. To determine if the desmosomal cadherins and plakoglobin interact with the amino-terminal domain of desmoplakin, these proteins were co-expressed in L-cell fibroblasts, cells that do not normally express desmosomal components. When expressed in L-cells, the desmosomal cadherins and plakoglobin exhibited a diffuse distribution. However, in the presence of an amino-terminal desmoplakin polypeptide (DP-NTP), the desmosomal cadherins and plakoglobin were observed in punctate clusters that also contained DP-NTP. In addition, plakoglobin and DP-NTP were recruited to cell-cell interfaces in L-cells co-expressing a chimeric cadherin with the E-cadherin extracellular domain and the desmoglein-1 cytoplasmic domain, and these cells formed structures that were ultrastructurally similar to the outer plaque of the desmosome. In transient expression experiments in COS cells, the recruitment of DP-NTP to cell borders by the chimera required co-expression of plakoglobin. Plakoglobin and DP-NTP co-immunoprecipitated when extracted from L-cells, and yeast two hybrid analysis indicated that DP-NTP binds directly to plakoglobin but not Dsg1. These results identify a role for desmoplakin in organizing the desmosomal cadherin-plakoglobin complex and provide new insights into the hierarchy of protein interactions that occur in the desmosomal plaque.
The Belle II experiment is expected to produce 50 times more data than the existing Belle experiment. Such huge data production requires not only scalability with respect to the storage service but ...also scalability regarding the metadata service. There has already been a metadata service at the Belle experiment, but it is not proper for the Belle II experiment because it has scalability problems and it is not intended to be used in a distributed grid environment. To deal with these issues, we designed an advanced metadata service system based on AMGA, which provides efficient and scalable metadata searching. We have built testbed sites to test the correctness, performance and scalability of the advanced metadata service system, and it has been proved to be able to provide efficient metadata searching for the Belle II experiment. The Belle II experiment is expected to produce 50 times more data than the existing Belle experiment. Such huge data production requires not only scalability with respect to the storage service but also scalability regarding the metadata service. There has already been a metadata service at the Belle experiment, but it is not proper for the Belle II experiment because it has scalability problems and it is not intended to be used in a distributed grid environment. To deal with these issues, we designed an advanced metadata service system based on AMGA, which provides efficient and scalable metadata searching. We have built testbed sites to test the correctness, performance and scalability of the advanced metadata service system, and it has been proved to be able to provide efficient metadata searching for the Belle II experiment. KCI Citation Count: 2
We have developed a metadata service for the Belle experiment which provides a mechanism to locate files using descriptive information. However, for the Belle II experiment, we will have 50–60 times ...more data. This metadata service may have problems with performance, scalability, and durability when employed at Belle II. These issues are compounded when metadata searches are extended to the event-level. Accordingly, we have designed a new metadata scheme for Belle II which significantly reduces disk space and propose a new metadata service which provides good performance and scalability based on AMGA (Arda Metadata catalog for Grid Application). We find that the use of event-level metadata provides an efficient scheme for processing events with many tracks.
Over the last few years great progress has been made in the technological development of Monolithic Active Pixel Sensors (MAPS) such that upgrades to existing vertex detectors using this technology ...are now actively being considered. Future vertex detection at an upgraded KEK-B factory, already the highest luminosity collider in the world, will require a detector technology capable of withstanding the increased track densities and larger radiation exposures. Near the beam pipe the current silicon strip detectors have projected occupancies in excess of 100%. Deep sub-micron MAPS look very promising to address this problem. In the context of an upgrade to the Belle vertex detector, the major obstacles to realizing such a device have been concerns about radiation hardness and readout speed. Two prototypes implemented in the TSMC 0.35
μm process have been developed to address these issues. Denoted the Continuous Acquisition Pixel, or CAP, the two variants of this architecture are distinguished in that CAP2 includes an 8-deep sampling pipeline within each 22.5
μm
2 pixel. Preliminary test results and remaining R&D issues are presented.
Desmosomes are adhesive intercellular junctions that act as cell surface attachment sites for intermediate filaments. The
desmosomal glycoproteins, desmogleins and desmocollins, are members of the ...cadherin family of adhesion molecules. In addition,
desmoglein has been shown to coimmunoprecipitate with the junctional protein plakoglobin. To characterize further the interaction
between plakoglobin and the desmosomal cadherins, stable mouse fibroblast (L-cells) cell lines were generated that express
plakoglobin, desmoglein and plakoglobin, or desmocollin and plakoglobin. L-cell lines transfected with a plasmid encoding
human plakoglobin expressed plakoglobin mRNA but very little plakoglobin protein. However, plakoglobin protein was expressed
at high levels in L-cells coexpressing either desmoglein or desmocollin. In addition, both desmocollin and desmoglein were
found to coimmunoprecipitate with plakoglobin. The transient expression of desmoglein in L-cell lines expressing plakoglobin
mRNA resulted in the formation of a complex between plakoglobin and desmoglein and in the accumulation of plakoglobin protein.
Furthermore, the rate of plakoglobin protein degradation was decreased by 15-20-fold in cell lines expressing either desmoglein
or desmocollin. These results demonstrate that the desmosomal cadherins posttranslationally regulate plakoglobin expression
by decreasing the rate of plakoglobin degradation.
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