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101.
Püsküllüoglu M Lukasiewicz E Miekus K Jarocha D Majka M 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2010,48(4):671-677
Rhabdomyosarcoma (RMS) represents the most common sarcoma of soft tissue among children. Two main RMS subtypes are alveolar (ARMS) and embryonal (ERMS). The major goal of this study was to find differentially expressed genes between RMS subtypes that could explain higher metastatic potential in ARMS and would be useful for the differential diagnosis. Using RQ-PCR analysis we compared expression of Snail1 and Snail-related genes among 7 ARMS and 8 ERMS patients' samples obtained from the primary tumors and among 2 alveolar and 2 embryonal cell lines. Our results show that Snail1 is highly expressed both in ARMS patients' samples and the alveolar cell lines. We also found that the expression of E-Cadherin was downregulated and the expression of Matrix Metalloproteinases 2 and 9 (MMP-2 and MMP-9) was upregulated in ARMS. We assume that, as in many tumors, also in RMS Snail1 acts as a regulator for pathways known for their role in cells' metastasis and that Snail1 activity results in increased MMPs and decreased E-Cadherin expression. Our findings may explain higher ARMS aggressiveness. Moreover, we suggest that further studies should be performed to verify if Snail1 can be considered as a potential target for ARMS therapy. 相似文献
102.
Werner Ulrich Izabela Hajdamowicz Marcin Zalewski Marzena Stańska Wojciech Ciurzycki Piotr Tykarski 《Ecological Research》2010,25(2):375-381
Competition theory predicts that species of similar ecological niches are less likely to coexist than species with different
niches, a process called species assortment. In contrast, the concept of habitat filtering implies that species with similar
ecological requirements should co-occur more often than expected by chance. Here we use environmental and ecological data
to assess patterns of co-occurrence of regional communities of spiders distributed across two assemblies of lake islands in
northern Poland. We found aggregated and random co-occurrences of species of the same genus and a significant tendency of
species segregation across genera. We also found that species of the same genus react similarly to important environmental
variables. A comparison of ecological traits of species of the local communities with those expected from a random sample
from the regional Polish species pool corroborated partly the habitat filtering hypothesis. On the other hand, we did not
find evidence for species assortment. Our results also imply that at least some observed species co-occurrences result from
niche differentiation. 相似文献
103.
Chih-Wen Shu Marcin Drag Miklos Bekes Dayong Zhai Guy S Salvesen John C Reed 《Autophagy》2010,6(7):936-947
Atg4 cysteine proteases (autophagins) play crucial roles in autophagy by proteolytic activation of Atg8 paralogs for targeting to autophagic vesicles by lipid conjugation, as well as in subsequent deconjugation reactions. However, the means to measure the activity of autophagins is limited. Herein, we describe two novel substrates for autophagins suitable for a diversity of in vitro assays, including (i) fluorogenic tetrapeptide acetyl-Gly-L-Thr-L-Phe-Gly-AFC (Ac-GTFG-AFC) and (ii) a fusion protein comprised of the natural substrate LC3B appended to the N-terminus of phospholipase A2 (LC3B-PLA2), which upon cleavage releases active PLA2 for fluorogenic assay. To generate the synthetic tetrapeptide substrate, the preferred tetrapeptide sequence recognized by autophagin-1/Atg4B was determined using a positional scanning combinatorial fluorogenic tetrapeptide library. With the LC3B-PLA2 substrate, we show that mutation of the glycine proximal to the scissile bond in LC3B abolishes activity. Both substrates showed high specificity for recombinant purified autophagin-1/Atg4B compared to closely related proteases and the LC3B-PLA2 substrate afforded substantially higher catalytic rates (kcat/Km 5.26 × 105 M−1/sec−1) than Ac-GTFG-AFC peptide (0.92 M−1/sec−1), consistent with substrate-induced activation. Studies of autophagin-1 mutants were also performed, including the protease lacking a predicted autoinhibitory domain at residues 1 to 24 and lacking a regulatory loop at residues 259 to 262. The peptide and fusion protein substrates were also employed for measuring autophagin activity in cell lysates, showing a decrease in cells treated with autophagin-1/Atg4B siRNA or transfected with a plasmid encoding Atg4B (Cys74Ala) dominant-negative. Therefore, the synthetic substrates for autophagins reported here provide new research tools for studying autophagy.Key words: autophagin, fluorogenic assay, tetrapeptide, phospholipase A2, LC3 相似文献
104.
Muskrat (Ondatra zibethicus) decline after the expansion of American mink (Neovison vison) in Poland
Marcin Brzeziński Jerzy Romanowski Michał Żmihorski Karolina Karpowicz 《European Journal of Wildlife Research》2010,56(3):341-348
Field survey data in Central Poland revealed that the proportion of sites inhabited by muskrats decreased from 44% to 7% over one decade. This corresponded to the decline in hunting bags of muskrat over the whole of Poland. The largest hunting harvest of muskrat was recorded in 1987/1988 (66,416 individuals), the smallest in 2007/2008 (4,567 individuals). The decline in hunting bags occurred in all regions analysed; however, it was most rapid in the north and north-east. Before the expansion of mink, which started in northern Poland at the beginning of the 1980s, muskrat densities in particular regions depended on the availability of aquatic habitats. A comparison of hunting bags of muskrat and American mink in years 2002–2008 indicated a significant negative correlation between the numbers of these two species harvested in seven regions of Poland. The negative correlation between numbers of muskrat and mink suggests that mink predation is one of the most important factors in the decline of the muskrat population in Poland. 相似文献
105.
106.
Spectrin and ankyrin are the key components of the erythrocyte cytoskeleton. The recently published crystal structure of the spectrin-ankyrin complex has indicated that their binding involves complementary charge interactions as well as hydrophobic interactions. However, only the former is supported by biochemical evidence. We now show that nonpolar interactions are important for high affinity complex formation, excluding the possibility that the binding is exclusively mediated by association of distinctly charged surfaces. Along these lines we report that substitution of a single hydrophobic residue, F917S in ankyrin, disrupts the structure of the binding site and leads to complete loss of spectrin affinity. Finally, we present data showing that minimal ankyrin binding site in spectrin is formed by helix 14C together with the loop between helices 15 B/C. 相似文献
107.
Bielawska-Drózd A Niemcewicz M Gaweł J Bartoszcze M Graniak G Joniec J Kołodziej M 《Medycyna do?wiadczalna i mikrobiologia》2010,62(4):351-360
Tularemia is highly infectious and fatal zoonotic disease caused by Gram negative bacteria Francisella tularensis. The necessity to undergo medical treatment in early phase of illness in humans and possibility of making use of bacterial aerosol by terrorists in an attack create an urgent need to implement a rapid and effective method which enables to identify the agent. In our study two primers FopA F/R and hybridization probes FopA S1/S2 designed from fopA gene sequence, were tested for their potential applicability to identify F. tularensis. In this research 50 strains of F. tularensis were used and the test gave positive results. Reaction specificity was confirmed by using of non-Francisella tularensis bacterial species. The results obtained in the real-time PCR reaction with primers Tul4 F/R and hybridization probes Tul4 S1/S2, designed from tul4 gene, were comparable to the results from previous experiment with fopA - primers set. Investigation of fopA and tul4 primers and hybridization probes properties revealed characteristic Tm (melting temperature) value of the products--61 degrees C and 60 degrees C, respectively. Detection sensitivity was remarkably higher when fopA primers set was used 1 fg/microl, and for tul4 primers set, minimal detectable concentration is 10 fg/microl. 相似文献
108.
mRNA decapping is promoted by an RNA-binding channel in Dcp2 总被引:1,自引:0,他引:1
Deshmukh MV Jones BN Quang-Dang DU Flinders J Floor SN Kim C Jemielity J Kalek M Darzynkiewicz E Gross JD 《Molecular cell》2008,29(3):324-336
Cap hydrolysis by Dcp2 is a critical step in several eukaryotic mRNA decay pathways. Processing requires access to cap-proximal nucleotides and the coordinated assembly of a decapping mRNP, but the mechanism of substrate recognition and regulation by protein interactions have remained elusive. Using NMR spectroscopy and kinetic analyses, we show that yeast Dcp2 resolves interactions with the cap and RNA body using a bipartite surface that forms a channel intersecting the catalytic and regulatory Dcp1-binding domains. The interaction with cap is weak but specific and requires binding of the RNA body to a dynamic interface. The catalytic step is stimulated by Dcp1 and its interaction domain, likely through a substrate-induced conformational change. Thus, activation of the decapping mRNP is restricted by access to 5'-proximal nucleotides, a feature that could act as a checkpoint in mRNA metabolism. 相似文献
109.
Anna Gumieniczek Hanna Hopkała Marcin Pruchniak 《Central European Journal of Biology》2007,2(4):538-546
In the present study, the induction of oxidative stress was examined in the testis of alloxan-induced diabetic rabbits. In
addition, the protective effect of repaglinide, an oral anti-diabetic, at a dose of 1 mg daily was studied after four and
eight weeks of the treatment. For these purposes, the levels of superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione
peroxidase (GSH-Px), glutathione reductase (GSSG-R), glutathione (GSH), ascorbic acid (AA), lipid peroxidation products (LPO)
and protein carbonyl groups (PCG) were quantified. Hyperglycemia resulted in significant increases in the antioxidative enzymes,
Cu, Zn-SOD, CAT, GSH-Px, and GSSG-R after four and eight weeks, respectively. There was also an increase in GSH level, and
a decrease in the level of AA. These effects were accompanied by an elevation in testicular LPO levels and PCG levels. Repaglinide
was found to normalize the activity of GSSG-R and levels of GSH and AA, and blunted the increased lipid peroxidation, however
no decrease in PCG levels were observed. In conclusion, some oxidative changes provoked in the testis of rabbits by hyperglycemia,
were found to be reduced with repaglinide treatment at therapeutic dose. 相似文献
110.
Dos Vultos T Mestre O Rauzier J Golec M Rastogi N Rasolofo V Tonjum T Sola C Matic I Gicquel B 《PloS one》2008,3(2):e1538