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The goal of this review is to highlight how emerging new models of filopodia assembly which include tissue specific actin-bundling proteins could provide more comprehensive representations of filopodia assembly that would describe more adequately and effectively the complexity and plasticity of epithelial cells. This review also describes how the true diversity of actin bundling proteins must be considered to predict the far-reaching significance and versatile functions of filopodia in epithelial cells.Key words: epithelial cell, fascin, villin, actin bundling, PIP2 binding, collective cell migration, microvilli, EMT, metastases 相似文献
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Pelagic, littoral, and terrestrial resources can all play a role in supporting consumers in lakes. The role of benthic algal-derived
food web pathways in lakes is perhaps the least understood because limnologists have historically focused on pelagic (open-water)
production and processes. We compiled carbon stable isotope data from 546 fish populations (75 lakes), and used a two end-member
mixing model to calculate littoral–benthic reliance for each fish species in each lake. Fish littoral–benthic reliance values
were averaged by lake to assess overall fish species benthic reliance for each lake. Lake-specific mean littoral reliance
(BRL; fish species not weighted according to production or biomass) averaged 57% and was independent of lake morphological and
limnological attributes. For these same lakes, water column nutrients, light, and morphometry data were used to estimate whole-lake
benthic algal and phytoplankton primary production. On average, benthic algae comprised 36% of whole-lake primary production
(BPf = 0.36). BPf and BRL were weakly correlated: BRL tends to be high even in large/deep lakes in which benthic algae is a minor contributor to whole-lake primary production.
The high littoral–benthic contribution to individual fish species appears to reflect the high concentration of fish species
diversity in the littoral zone. Our work cannot be extrapolated to whole-lake fish production. However, the result is consistent
with other work indicating that most fish species inhabit the littoral zone, whereas relatively few exclusively inhabit the
pelagic. Our results suggest that it takes less primary production to support a single fish species in the littoral zone than
is required to support a species in the pelagic. 相似文献
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Anup Jose Suman Labala Kunal Manoj Ninave Sudeep Kumar Gade Venkata Vamsi Krishna Venuganti 《AAPS PharmSciTech》2018,19(1):166-175
The aim of the present study was to evaluate the effectiveness of iontophoretic co-delivery of curcumin and anti-STAT3 siRNA using cationic liposomes against skin cancer. Curcumin was encapsulated in DOTAP-based cationic liposomes and then complexed with STAT3 siRNA. This nanocomplex was characterized for the average particle size, zeta-potential, and encapsulation efficiency. The cell viability studies in B16F10 mouse melanoma cells have shown that the co-delivery of curcumin and STAT3 siRNA significantly (p < 0.05) inhibited the cancer cell growth compared with either liposomal curcumin or STAT3 siRNA alone. The curcumin-loaded liposomes were able to penetrate up to a depth of 160 μm inside the skin after iontophoretic (0.47 mA/cm2) application. The in vivo efficacy studies were performed in the mouse model of melanoma skin cancer. Co-administration of the curcumin and STAT3 siRNA using liposomes significantly (p < 0.05) inhibited the tumor progression as measured by tumor volume and tumor weight compared with either liposomal curcumin or STAT3 siRNA alone. Furthermore, the iontophoretic administration of curcumin-loaded liposome-siRNA complex showed similar effectiveness in inhibiting tumor progression and STAT3 protein suppression compared with intratumoral administration. Taken together, cationic liposomes can be utilized for topical iontophoretic co-delivery of small molecule and siRNA for effective treatment of skin diseases. 相似文献
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Amit K. Chaturvedi Amit Kumar Verma Jay Prakash Thakur Sudeep Roy Shashi Bhushan Tripathi Balagani Sathish Kumar Sadiya Khwaja Naresh K. Sachan Ashok Sharma Debabrata Chanda Karuna Shanker Dharmendra Saikia Arvind S. Negi 《Bioorganic & medicinal chemistry》2018,26(15):4551-4559
Arylbenzimidazoles have been synthesized as antimycobacterial agents. An efficient synthesis has been developed for 2-arylbenzimidazoles from o-phenylenediamines and aromatic aldehydes in molecular sieves-methanol system. The methodology is straightforward to get 2-arylbenzimidazoles (3a–3z) in excellent yields with high chemoselectivity over 2-aryl-1-benzylbenzimidazoles (4a–4z). All these benzimidazole analogues were evaluated against M. tuberculosis in BACTEC radiometric assay. The compounds 4y and 4z exhibited potential antitubercular activity against M. tuberculosis H37RV, MIC at 16?µM and 24?µM respectively. The best compound of the series i.e. compound 4y was well tolerated by Swiss-albino mice in acute oral toxicity. Compound 4y possessing a diarylbenzimidazole core, can further be optimized for better activity. 相似文献
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Margarita Orejas rew Peter MacCabe José Antonio Pérez González Sudeep Kumar & Daniel Ramón 《Molecular microbiology》1999,31(1):177-184
Expression of the Aspergillus nidulans 22 kDa endoxylanase gene, xlnA , is controlled by at least three mechanisms: specific induction by xylan or xylose; carbon catabolite repression (CCR); and regulation by ambient pH. Deletion analysis of xlnA upstream sequences has identified two positively acting regions: one that mediates specific induction by xylose; and another that mediates the influence of ambient pH and contains two PacC consensus binding sites. The extreme derepressed mutation creAd 30 results in considerable, although not total, loss of xlnA glucose repressibility, indicating a major role for CreA in its CCR. Three consensus CreA binding sites are present upstream of the structural gene. Point mutational analysis using reporter constructs has identified a single site, xlnA .C1, that is responsible for direct CreA repression in vivo . Using the creAd 30 derepressed mutant background, our results indicate the existence of indirect repression by CreA. 相似文献
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Sudeep Bhattacharyya Amy Kerzmann Andrew L Feig 《European journal of biochemistry》2002,269(14):3425-3432
Uridine-5'-diphospho-1-alpha-d-glucose (UDP-Glc) is a common substrate used by glucosyltransferases, including certain bacterial toxins such as Toxins A and B from Clostridium difficile. Fluorescent analogs of UDP-Glc have been prepared for use in our studies of the clostridial toxins. These compounds are related to the methylanthraniloyl-ATP compounds commonly used to probe the chemistry of ATP-dependent enzymes. The reaction of excess methylisatoic anhydride with UDP-Glc in aqueous solution yields primarily the 2' and 3' isomers of methylanthraniloyl-UDP-Glc (MUG). As the 2' and 3' isomers readily interconvert, this isomeric mixture was copurified by HPLC away from the other isomeric products, and was characterized by a combination of NMR, fluorescence and mass spectrometric methods. TcdA binds MUG competitively with respect to UDP-Glc with an affinity of 15 +/- 2 microm in the absence of Mg2+. There is currently no evidence that the fluorescent substrate analog is turned over by the toxin in either glucosyltransferase or glucosylhydrolase reactions. Using a competition assay, the affinity of UDP-Glc was determined to be 45+/-10 microm in the absence of Mg2+. The binding of UDP-Glc and Mg2+ are highly coupled with Mg2+ affinities in the range of 90-600 microm, depending on the experimental conditions. These results imply that one of the significant roles of the metal ion might be to stabilize the enzyme-substrate complex prior to initiation of the transferase chemistry. 相似文献
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Regulation of cell structure and function by actin-binding proteins: villin's perspective 总被引:1,自引:0,他引:1
Villin is a tissue-specific actin modifying protein that is associated with actin filaments in the microvilli and terminal web of epithelial cells. It belongs to a large family of actin-binding proteins which includes actin-capping, -nucleating and/or -severing proteins such as gelsolin, severin, fragmin, adseverin/scinderin and actin crosslinking proteins such as dematin and supervillin. Studies done in epithelial cell lines and villin knock-out mice have demonstrated the function of villin in regulating actin dynamics, cell morphology, epithelial-to-mesenchymal transition, cell migration and cell survival. In addition, the ligand-binding properties of villin (F-actin, G-actin, calcium, phospholipids and phospholipase C-gamma1) are mechanistically important for the crosstalk between signaling pathways and actin reorganization in epithelial cells. 相似文献