550 research outputs found
Signal Transduction by Cell Adhesion Receptors, Integrins
Interactions of cells with basement
membranes and the extracellular matrices
are crucial for various biological
processes, including the maintenance
of tissue integrity, embryogenesis,
wound healing, and the metastasis
of tumor cells. These processes
involve cell adhesion and migration.
Adhesive and migratory events
require certain biochemical entities,
formation of multiprotein complex
between these entities, and their functional
communication one another.
Cell adhesion is mediated through
cell adhesion receptors or transmembrane
glycoproteins binding to
extracellular matrix (ECM) or counterreceptors
on neighbor cells. Cell
adhesion receptor families include
cadherins, selectins, syndecans, and
the immunoglobulin superfamily of
cell adhesion molecules (IgCAMs).
In this review, integrin-mediated cellular
processes such as cell proliferation
and apoptosis and their molecular
basis will be discussed based
on recent observations, although other cell adhesion receptors can play
important roles or be involved in the
processes and recent outstanding
reviews are also availableOAIID:oai:osos.snu.ac.kr:snu2003-01/102/0000003910/2SEQ:2PERF_CD:SNU2003-01EVAL_ITEM_CD:102USER_ID:0000003910ADJUST_YN:NEMP_ID:A078142DEPT_CD:375CITE_RATE:0FILENAME:논단_review.pdfDEPT_NM:약학과EMAIL:[email protected]:
The Fit between Client IT Capability and Vendor Competence and Its Impact on Outsourcing Success
This study investigates the impact of client firm’s IT capability, vendor firm’s competence and their fit on the outsourcing success. In theory building, by concretizing the concepts of IT capability and competence based on the resource-based view, the importance of fit between the client’s IT capability and the vendor’s competence is emphasized. We then hypothesize that both factors are stronger together than the individual impact of either the client’s IT capability or the vendor’s competence. For validation, 267 client-vendor-matched-pair data were collected. To avoid potential imbalance caused by the bilateral perspective, an exploratory approach, all-possible-subsets-regression method was adopted. The results reveal that the vendor’s competence is the most significant factor in outsourcing success, but interestingly, the fit between vendor competence and the client’s IT capability is the second most important. The client’s IT capability also has a positive impact on outsourcing success but with the smallest explanation power
Nischarin, a Novel Protein That Interacts with the Integrin α5 Subunit and Inhibits Cell Migration
Integrins have been implicated in key cellular functions, including cytoskeletal organization, motility, growth, survival, and control of gene expression. The plethora of integrin α and β subunits suggests that individual integrins have unique biological roles, implying specific molecular connections between integrins and intracellular signaling or regulatory pathways. Here, we have used a yeast two-hybrid screen to identify a novel protein, termed Nischarin, that binds preferentially to the cytoplasmic domain of the integrin α5 subunit, inhibits cell motility, and alters actin filament organization. Nischarin is primarily a cytosolic protein, but clearly associates with α5β1, as demonstrated by coimmunoprecipitation. Overexpression of Nischarin markedly reduces α5β1-dependent cell migration in several cell types. Rat embryo fibroblasts transfected with Nischarin constructs have “basket-like” networks of peripheral actin filaments, rather than typical stress fibers. These observations suggest that Nischarin might affect signaling to the cytoskeleton regulated by Rho-family GTPases. In support of this, Nischarin expression reverses the effect of Rac on lamellipodia formation and selectively inhibits Rac-mediated activation of the c-fos promoter. Thus, Nischarin may play a negative role in cell migration by antagonizing the actions of Rac on cytoskeletal organization and cell movement
Absolute decision corrupts absolutely: conservative online speaker diarisation
Our focus lies in developing an online speaker diarisation framework which
demonstrates robust performance across diverse domains. In online speaker
diarisation, outputs generated in real-time are irreversible, and a few
misjudgements in the early phase of an input session can lead to catastrophic
results. We hypothesise that cautiously increasing the number of estimated
speakers is of paramount importance among many other factors. Thus, our
proposed framework includes decreasing the number of speakers by one when the
system judges that an increase in the past was faulty. We also adopt dual
buffers, checkpoints and centroids, where checkpoints are combined with
silhouette coefficients to estimate the number of speakers and centroids
represent speakers. Again, we believe that more than one centroid can be
generated from one speaker. Thus we design a clustering-based label matching
technique to assign labels in real-time. The resulting system is lightweight
yet surprisingly effective. The system demonstrates state-of-the-art
performance on DIHARD 2 and 3 datasets, where it is also competitive in AMI and
VoxConverse test sets.Comment: 5pages, 2 figure, 4 tables, submitted to ICASS
High-resolution embedding extractor for speaker diarisation
Speaker embedding extractors significantly influence the performance of
clustering-based speaker diarisation systems. Conventionally, only one
embedding is extracted from each speech segment. However, because of the
sliding window approach, a segment easily includes two or more speakers owing
to speaker change points. This study proposes a novel embedding extractor
architecture, referred to as a high-resolution embedding extractor (HEE), which
extracts multiple high-resolution embeddings from each speech segment. Hee
consists of a feature-map extractor and an enhancer, where the enhancer with
the self-attention mechanism is the key to success. The enhancer of HEE
replaces the aggregation process; instead of a global pooling layer, the
enhancer combines relative information to each frame via attention leveraging
the global context. Extracted dense frame-level embeddings can each represent a
speaker. Thus, multiple speakers can be represented by different frame-level
features in each segment. We also propose an artificially generating mixture
data training framework to train the proposed HEE. Through experiments on five
evaluation sets, including four public datasets, the proposed HEE demonstrates
at least 10% improvement on each evaluation set, except for one dataset, which
we analyse that rapid speaker changes less exist.Comment: 5pages, 2 figure, 3 tables, submitted to ICASS
The Effects of Loranthus parasiticus
This study is undertaken to evaluate cognitive enhancing effect and neuroprotective effect of Loranthus parasiticus. Cognitive enhancing effect of Loranthus parasiticus was investigated on scopolamine-induced amnesia model in Morris water maze test and passive avoidance test. We also examined the neuroprotective effect on glutamate-induced cell death in HT22 cells by MTT assay. These results of Morris water maze test and passive avoidance test indicated that 10 and 50 mg/kg of Loranthus parasiticus reversed scopolamine-induced memory deficits. Loranthus parasiticus also protected against glutamate-induced cytotoxicity in HT22 cells. As a result of in vitro test for elucidating possible mechanism, Loranthus parasiticus inhibited AChE activity, ROS production, and Ca2+ accumulation. Loranthus parasiticus showed memory enhancing effect and neuroprotective effect and these effects may be related to inhibition of AChE activity, ROS level, and Ca2+ influx
The COOH-terminus of TM4SF5 in hepatoma cell lines regulates c-Src to form invasive protrusions via EGFR Tyr845 phosphorylation
AbstractTransmembrane 4 L six family member 5 (TM4SF5) enhances cell migration and invasion, although how TM4SF5 mechanistically mediates these effects remains unknown. In the study, during efforts to understand TM4SF5-mediated signal transduction, TM4SF5 was shown to bind c-Src and thus hepatoma cell lines expressing TM4SF5 were analyzed for the significance of the interaction in cell invasion. The C-terminus of TM4SF5 bound both inactive c-Src that might be sequestered to certain cellular areas and active c-Src that might form invasive protrusions. Wildtype (WT) TM4SF5 expression enhanced migration and invasive protrusion formation in a c-Src-dependent manner, compared with TM4SF5-null control hepatoma cell lines. However, tailless TM4SF5ΔC cells were more efficient than WT TM4SF5 cells, suggesting a negative regulatory role by the C-terminus. TM4SF5 WT- or TM4SF5ΔC-mediated formation of invasive protrusions was dependent or independent on serum or epidermal growth factor treatment, respectively, although they both were dependent on c-Src. The c-Src activity of TM4SF5 WT- or TM4SF5ΔC-expressing cells correlated with enhanced Tyr845 phosphorylation of epidermal growth factor receptor. Y845F EGFR mutation abolished the TM4SF5-mediated invasive protrusions, but not c-Src phosphorylation. Our findings demonstrate that TM4SF5 modulates c-Src activity during TM4SF5-mediated invasion through a TM4SF5/c-Src/EGFR signaling pathway, differentially along the leading protrusive edges of an invasive cancer cell
Nischarin, a Novel Protein That Interacts with the Integrin α5 Subunit and Inhibits Cell Migration
Integrins have been implicated in key cellular functions, including cytoskeletal organization, motility, growth, survival, and control of gene expression. The plethora of integrin α and β subunits suggests that individual integrins have unique biological roles, implying specific molecular connections between integrins and intracellular signaling or regulatory pathways. Here, we have used a yeast two-hybrid screen to identify a novel protein, termed Nischarin, that binds preferentially to the cytoplasmic domain of the integrin α5 subunit, inhibits cell motility, and alters actin filament organization. Nischarin is primarily a cytosolic protein, but clearly associates with α5β1, as demonstrated by coimmunoprecipitation. Overexpression of Nischarin markedly reduces α5β1-dependent cell migration in several cell types. Rat embryo fibroblasts transfected with Nischarin constructs have “basket-like” networks of peripheral actin filaments, rather than typical stress fibers. These observations suggest that Nischarin might affect signaling to the cytoskeleton regulated by Rho-family GTPases. In support of this, Nischarin expression reverses the effect of Rac on lamellipodia formation and selectively inhibits Rac-mediated activation of the c-fos promoter. Thus, Nischarin may play a negative role in cell migration by antagonizing the actions of Rac on cytoskeletal organization and cell movement
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