Departments View all
Recent Publications View all
- SourceAvailable from: Przemysław Glaza[Show abstract] [Hide abstract]
ABSTRACT: HtrA3 protease belongs to the high-temperature requirement A (HtrA) family of serine proteases which take part in cellular stress response including heat shock, inflammation and cancer. HtrA3 is composed of an N-terminal domain not required for proteolytic activity, a central serine protease domain and a C-terminal PDZ domain. The latter serves as a substrate or regulator binding domain and may participate in oligomerization. HtrA3S, its short natural isoform, lacks the PDZ domain which is substituted by a stretch of 7 C-terminal amino acid residues, unique for this isoform. Down-regulation of HtrA3 in tumors, shown by other groups and us, suggests HtrA3s involvement in oncogenesis . HtrA3 acts as a proapoptotic protein and is suggested to function as a tumor suppressor. It promotes cytotoxicity of etoposide and cisplatin in lung cancer cell lines [2,3]. To date, HtrA3 has been poorly characterized from the biochemical point of view, mainly due to the fact that it is difficult to purify recombinant HtrA3. We were able to express in bacterial system and purify HtrA3 in quantities sufficient to perform structural studies. The aim of this study was to characterize and compare the proteolytic properties and quaternary structure of the HtrA3 isoforms. Both studied isoforms lacked the N-terminal domain. HtrA3 with the PDZ domain removed (HtrA3-PDZ) and HtrA3S (HtrA3S) were fully active at a wide range of temperatures and their substrate affinity was not impaired. This indicates that the PDZ domain is dispensable for HtrA3 activity. As determined by size exclusion chromatography,HtrA3 formed stable trimers while both HtrA3-PDZ and HtrA3S were monomeric. This suggests that the presence of the PDZ domain, unlike in other human HtrAs (HtrA1 and HtrA2), influences HtrA3 trimer formation. The unique C-terminal sequence of N-HtrA3S appeared to have little effect on activity and oligomerization . References: 1. Skórko-Glonek J et al. (2013) Curr Pharm Des 19: 977-1009. 2. Beleford D et al. (2010) Clin Cancer Res 16: 398-409. 3. Beleford D et al. (2010) J Biol Chem 285:12011-27. 4. Glaza P et al. (2015) PLoS ONE doi: 10.1371/journal.pone.0131142.
- [Show abstract] [Hide abstract]
ABSTRACT: A novel in situ X-ray fluorescence microscopy combined with X-ray absorption spectroscopy technique is reported to investigate the Li–S batteries during electrochemical cycling. The evolution of morphology changes of the electrode is monitored in real time using the X-ray fluorescence images, while the changes of the sulfur chemical state are characterized simultaneously using the X-ray absorption spectroscopy spectra.
- [Show abstract] [Hide abstract]
ABSTRACT: Identifying land-use drivers of changes in river condition is complicated by spatial scale, geomorphological context, land management, and correlations among responding variables such as nutrients and sediments. Furthermore, variations in standard metrics, such as substratum composition, do not necessarily relate causally to ecological impacts. Consequently, the absence of a significant relationship between a hypothesised driver and a dependent variable does not necessarily indicate the absence of a causal relationship. We conducted a gradient survey to identify impacts of catchment-scale grazing by domestic livestock on river macroinvertebrate communities. A standard correlative approach showed that community structure was strongly related to the upstream catchment area under grazing. We then used data from a stream mesocosm experiment that independently quantified the impacts of nutrients and fine sediments on macroinvertebrate communities to train artificial neural networks (ANNs) to assess the relative influence of nutrients and fine sediments on the survey sites from their community composition. The ANNs developed to predict nutrient impacts did not find a relationship between nutrients and catchment area under grazing, suggesting that nutrients were not an important factor mediating grazing impacts on community composition, or that these ANNs had no generality or insufficient power at the landscape-scale. In contrast, ANNs trained to predict the impacts of fine sediments indicated a significant relationship between fine sediments and catchment area under grazing. Macroinvertebrate communities at sites with a high proportion of land under grazing were thus more similar to those resulting from high fine sediments in a mesocosm experiment than to those resulting from high nutrients. Our study confirms that 1) fine sediment is an important mediator of land-use impacts on river macroinvertebrate communities, 2) ANNs can successfully identify subtle effects and separate the effects of correlated variables, and 3) data from small-scale experiments can generate relationships that help explain landscape-scale patterns.
Information provided on this web page is aggregated encyclopedic and bibliographical information relating to the named institution. Information provided is not approved by the institution itself. The institution’s logo (and/or other graphical identification, such as a coat of arms) is used only to identify the institution in a nominal way. Under certain jurisdictions it may be property of the institution.
Rg score distribution
No data available.