References of "Schaffner, Elisabeth 50002993"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAngiotensin II regulates phosphorylation of actin-associated proteins in human podocytes
Schenk, Laura K; Möller-Kerutt, Annika; Klosowski, Rafael et al

in FASEB Journal (2017)

Within the kidney, angiotensin II (AngII) targets different cell types in the vasculature, tubuli, and glomeruli. An important part of the renal filtration barrier is composed of podocytes with their ... [more ▼]

Within the kidney, angiotensin II (AngII) targets different cell types in the vasculature, tubuli, and glomeruli. An important part of the renal filtration barrier is composed of podocytes with their actin-rich foot processes. In this study, we used stable isotope labeling with amino acids in cell culture coupled to mass spectrometry to characterize relative changes in the phosphoproteome of human podocytes in response to short-term treatment with AngII. In 4 replicates, we identified a total of 17,956 peptides that were traceable to 2081 distinct proteins. Bioinformatic analyses revealed that among the increasingly phosphorylated peptides are predominantly peptides that are related to actin filaments, cytoskeleton, lamellipodia, mammalian target of rapamycin, and MAPK signaling. Among others, this screening approach highlighted the increased phosphorylation of actin-bundling protein, L-plastin (LCP1). AngII-dependent phosphorylation of LCP1 in cultured podocytes was mediated by the kinases ERK, p90 ribosomal S6 kinase, PKA, or PKC. LCP1 phosphorylation increased filopodia formation. In addition, treatmentwith AngII led to LCP1 redistribution to the cell margins,membrane ruffling, and formation of lamellipodia. Our data highlight the importance of AngII-triggered actin cytoskeleton-associated signal transduction in podocytes. [less ▲]

Detailed reference viewed: 48 (8 UL)
Full Text
Peer Reviewed
See detailExpanding the Interactome of TES by Exploiting TES Modules with Different Subcellular Localizations
SALA, Stefano; Van troys, Marleen; Medves, Sandrine et al

in Journal of Proteome Research (2017), doi: 10.1021/acs.jproteome.7b00034

Detailed reference viewed: 52 (10 UL)
Full Text
Peer Reviewed
See detailL-plastin Ser5 phosphorylation in breast cancer cells and in vitro is mediated by RSK downstream of the ERK/MAPK pathway
Lommel, Maiti UL; Trairatphisan, Panuwat UL; Gäbler, Karoline UL et al

in FASEB Journal (2016)

Deregulated cell migration and invasion are hallmarks of metastatic cancer cells. Phosphorylation on residue Ser5 of the actin-bundling protein L-plastin activates L-plastin and has been reported to be ... [more ▼]

Deregulated cell migration and invasion are hallmarks of metastatic cancer cells. Phosphorylation on residue Ser5 of the actin-bundling protein L-plastin activates L-plastin and has been reported to be crucial for invasion and metastasis. Here, we investigate signal transduction leading to L-plastin Ser5 phosphorylation using 4 human breast cancer cell lines. Whole-genome microarray analysis comparing cell lines with different invasive capacities and corresponding variations in L-plastin Ser5 phosphorylation level revealed that genes of the ERK/MAPK pathway are differentially expressed. It is noteworthy that in vitro kinase assays showed that ERK/MAPK pathway downstream ribosomal protein S6 kinases α-1 (RSK1) and α-3 (RSK2) are able to directly phosphorylate L-plastin on Ser5. Small interfering RNA- or short hairpin RNA-mediated knockdown and activation/inhibition studies followed by immunoblot analysis and computational modeling confirmed that ribosomal S6 kinase (RSK) is an essential activator of L-plastin. Migration and invasion assays showed that RSK knockdown led to a decrease of up to 30% of migration and invasion of MDA-MB-435S cells. Although the presence of L-plastin was not necessary for migration/invasion of these cells, immunofluorescence assays illustrated RSK-dependent recruitment of Ser5-phosphorylated L-plastin to migratory structures. Altogether, we provide evidence that the ERK/MAPK pathway is involved in L-plastin Ser5 phosphorylation in breast cancer cells with RSK1 and RSK2 kinases able to directly phosphorylate L-plastin residue Ser5. [less ▲]

Detailed reference viewed: 133 (17 UL)
Full Text
Peer Reviewed
See detailDelineating the Tes Interaction Site in Zyxin and Studying Cellular Effects of Its Disruption
Hadzic, Ermin; Catillon, Marie UL; Halavatyi, Aliaksandr et al

in PLoS ONE (2015)

Detailed reference viewed: 51 (9 UL)
Full Text
Peer Reviewed
See detailInhibition of αIIbβ3 Ligand Binding by an αIIb Peptide that Clasps the Hybrid Domain to the βI Domain of β3
Lee, Wen Hwa; Schaffner, Elisabeth UL; Tsoukatos, Demokritos C et al

in PLoS ONE (2015)

Agonist-stimulated platelet activation triggers conformational changes of integrin αIIbβ3, allowing fibrinogen binding and platelet aggregation. We have previously shown that an octapeptide, p1YMESRADR8 ... [more ▼]

Agonist-stimulated platelet activation triggers conformational changes of integrin αIIbβ3, allowing fibrinogen binding and platelet aggregation. We have previously shown that an octapeptide, p1YMESRADR8, corresponding to amino acids 313-320 of the β-ribbon extending from the β-propeller domain of αIIb, acts as a potent inhibitor of platelet aggregation. Here we have performed in silico modelling analysis of the interaction of this peptide with αIIbβ3 in its bent and closed (not swing-out) conformation and show that the peptide is able to act as a substitute for the β-ribbon by forming a clasp restraining the β3 hybrid and βI domains in a closed conformation. The involvement of species-specific residues of the β3 hybrid domain (E356 and K384) and the β1 domain (E297) as well as an intrapeptide bond (pE315-pR317) were confirmed as important for this interaction by mutagenesis studies of αIIbβ3 expressed in CHO cells and native or substituted peptide inhibitory studies on platelet functions. Furthermore, NMR data corroborate the above results. Our findings provide insight into the important functional role of the αIIb β-ribbon in preventing integrin αIIbβ3 head piece opening, and highlight a potential new therapeutic approach to prevent integrin ligand binding. [less ▲]

Detailed reference viewed: 44 (5 UL)