Surface area of lipid membranes regulates the DNA-binding capacity of cationic liposomes

2009 ◽  
Vol 94 (3) ◽  
pp. 033903 ◽  
Author(s):  
Cristina Marchini ◽  
Maura Montani ◽  
Augusto Amici ◽  
Daniela Pozzi ◽  
Ruggero Caminiti ◽  
...  
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Diana M. Morales-Prieto ◽  
Stephanie Ospina-Prieto ◽  
Wittaya Chaiwangyen ◽  
Maja Weber ◽  
Sebastian Hölters ◽  
...  

Invasiveness of trophoblast and choriocarcinoma cells is in part mediated via leukemia inhibitory factor- (LIF-) induced activation of signal transducer and activator of transcription 3 (STAT3). The regulation of STAT3 phosphorylation at its ser727 binding site, possible crosstalk with intracellular MAPK signaling, and their functional implications are the object of the present investigation. JEG-3 choriocarcinoma cells were cultured in presence/absence of LIF and the specific ERK1/2 inhibitor (U0126). Phosphorylation of signaling molecules (p-STAT3 (ser727 and tyr705) and p-ERK1/2 (thr 202/tyr 204)) was assessed per Western blot. Immunocytochemistry confirmed results, but also pinpointed the location of phosphorylated signaling molecules. STAT3 DNA-binding capacity was studied with a colorimetric ELISA-based assay. Cell viability and invasion capability were assessed by MTS and Matrigel assays. Our results demonstrate that LIF-induced phosphorylation of STAT3 (tyr705 and ser727) is significantly increased after blocking ERK1/2. STAT3 DNA-binding capacity and cell invasiveness are enhanced after LIF stimulation and ERK1/2 blockage. In contrast, proliferation is enhanced by LIF but reduced after ERK1/2 inhibition. The findings herein show that blocking ERK1/2 increases LIF-induced STAT3 phosphorylation and STAT3 DNA-binding capacity by an intranuclear crosstalk, which leads to enhanced invasiveness and reduced proliferation.


2011 ◽  
Vol 108 (22) ◽  
pp. 9084-9088 ◽  
Author(s):  
M. Staykova ◽  
D. P. Holmes ◽  
C. Read ◽  
H. A. Stone

1976 ◽  
Vol 3 (11) ◽  
pp. 2971-2984 ◽  
Author(s):  
W. S. Kelly ◽  
N. D. F. Grindley

1992 ◽  
Vol 118 (4) ◽  
pp. 775-784 ◽  
Author(s):  
B Lüscher ◽  
R N Eisenman

The c-myc and c-myb proto-oncogenes encode phosphorylated nuclear DNA binding proteins that are likely to be involved in transcriptional regulation. Here we demonstrate that both Myc and Myb proteins are hyperphosphorylated during mitosis. In the case of Myb, hyperphosphorylation is accompanied by the appearance of three M phase-specific tryptic phosphopeptides. At least one of these phosphopeptides corresponds to a phosphopeptide generated after phosphorylation of Myb in vitro by p34cdc2 kinase. By contrast, the mitotic hyperphosphorylation of Myc does not correlate with the appearance of unique phosphopeptides, suggesting that M phase and interphase sites may be clustered within the same peptides. In addition Myc does not appear to be a target for p34cdc2 phosphorylation. The hyperphosphorylated forms of Myc and Myb from mitotic cells are functionally distinct from the corresponding interphase proteins in that the former have reduced ability to bind nonspecificially to double-stranded DNA cellulose. Furthermore, mitotic Myb binds poorly to oligodeoxynucleotides containing an Myb response element. We surmise that the decreased DNA binding capacity of hyperphosphorylated Myb and Myc during M phase may function to release these proteins from chromatin during chromosome condensation.


mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Begoña Monterroso ◽  
Silvia Zorrilla ◽  
Marta Sobrinos-Sanguino ◽  
Miguel Ángel Robles-Ramos ◽  
Carlos Alfonso ◽  
...  

ABSTRACTDivision ring formation at midcell is controlled by various mechanisms inEscherichia coli, one of them being the linkage between the chromosomal Ter macrodomain and the Z-ring mediated by MatP, a DNA binding protein that organizes this macrodomain and contributes to the prevention of premature chromosome segregation. Here we show that, during cell division, just before splitting the daughter cells, MatP seems to localize close to the cytoplasmic membrane, suggesting that this protein might interact with lipids. To test this hypothesis, we investigated MatP interaction with lipidsin vitro. We found that, when encapsulated inside vesicles and microdroplets generated by microfluidics, MatP accumulates at phospholipid bilayers and monolayers matching the lipid composition in theE. coliinner membrane. MatP binding to lipids was independently confirmed using lipid-coated microbeads and biolayer interferometry assays, which suggested that the recognition is mainly hydrophobic. Interaction of MatP with the lipid membranes also occurs in the presence of the DNA sequences specifically targeted by the protein, but there is no evidence of ternary membrane/protein/DNA complexes. We propose that the association of MatP with lipids may modulate its spatiotemporal localization and its recognition of other ligands.IMPORTANCEThe division of anE. colicell into two daughter cells with equal genomic information and similar size requires duplication and segregation of the chromosome and subsequent scission of the envelope by a protein ring, the Z-ring. MatP is a DNA binding protein that contributes both to the positioning of the Z-ring at midcell and the temporal control of nucleoid segregation. Our integratedin vivoandin vitroanalysis provides evidence that MatP can interact with lipid membranes reproducing the phospholipid mixture in theE. coliinner membrane, without concomitant recruitment of the short DNA sequences specifically targeted by MatP. This observation strongly suggests that the membrane may play a role in the regulation of the function and localization of MatP, which could be relevant for the coordination of the two fundamental processes in which this protein participates, nucleoid segregation and cell division.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1025 ◽  
Author(s):  
Rejhana Kolašinac ◽  
Sebastian Jaksch ◽  
Georg Dreissen ◽  
Andrea Braeutigam ◽  
Rudolf Merkel ◽  
...  

Lipid-based nanoparticles, also called vesicles or liposomes, can be used as carriers for drugs or many types of biological macromolecules, including DNA and proteins. Efficiency and speed of cargo delivery are especially high for carrier vesicles that fuse with the cellular plasma membrane. This occurs for lipid mixture containing equal amounts of the cationic lipid DOTAP and a neutral lipid with an additional few percents of an aromatic substance. The fusion ability of such particles depends on lipid composition with phosphoethanolamine (PE) lipids favoring fusion and phosphatidyl-choline (PC) lipids endocytosis. Here, we examined the effects of temperature, ionic strength, osmolality, and pH on fusion efficiency of cationic liposomes with Chinese hamster ovary (CHO) cells. The phase state of liposomes was analyzed by small angle neutron scattering (SANS). Our results showed that PC containing lipid membranes were organized in the lamellar phase. Here, fusion efficiency depended on buffer conditions and remained vanishingly small at physiological conditions. In contrast, SANS indicated the coexistence of very small (~50 nm) objects with larger, most likely lamellar structures for PE containing lipid particles. The fusion of such particles to cell membranes occurred with very high efficiency at all buffer conditions. We hypothesize that the altered phase state resulted in a highly reduced energetic barrier against fusion.


2016 ◽  
Vol 28 (5) ◽  
pp. 608 ◽  
Author(s):  
Wittaya Chaiwangyen ◽  
Stephanie Ospina-Prieto ◽  
Diana M. Morales-Prieto ◽  
Francisco Lazaro Pereira de Sousa ◽  
Jana Pastuschek ◽  
...  

Leukaemia inhibitory factor (LIF) and oncostatin M (OSM) are pleiotropic cytokines present at the implantation site that are important for the normal development of human pregnancy. These cytokines share the cell membrane receptor subunit gp130, resulting in similar functions. The aim of this study was to compare the response to LIF and OSM in several trophoblast models with particular regard to intracellular mechanisms and invasion. Four trophoblast cell lines with different characteristics were used: HTR-8/SVneo, JEG-3, ACH-3P and AC1-M59 cells. Cells were incubated with LIF, OSM (both at 10 ng mL–1) and the signal transducer and activator of transcription (STAT) 3 inhibitor S3I-201 (200 µM). Expression and phosphorylation of STAT3 (tyr705) and extracellular regulated kinase (ERK) 1/2 (thr202/204) and the STAT3 DNA-binding capacity were analysed by Western blotting and DNA-binding assays, respectively. Cell viability and invasiveness were assessed by the methylthiazole tetrazolium salt (MTS) and Matrigel assays. Enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 was investigated by zymography. OSM and LIF triggered phosphorylation of STAT3 and ERK1/2, followed by a significant increase in STAT3 DNA-binding activity in all tested cell lines. Stimulation with LIF but not OSM significantly enhanced invasion of ACH-3P and JEG-3 cells, but not HTR-8/SVneo or AC1-M59 cells. Similarly, STAT3 inhibition significantly decreased the invasiveness of only ACH-3P and JEG-3 cells concomitant with decreases in secreted MMP-2 and MMP-9. OSM shares with LIF the capacity to activate ERK1/2 and STAT3 pathways in all cell lines tested, but their resulting effects are dependent on cell type. This suggests that LIF and OSM may partially substitute for each other in case of deficiencies or therapeutic interventions.


2009 ◽  
Vol 23 (11) ◽  
pp. 3790-3807 ◽  
Author(s):  
Mohamed M. A. E. L. Salem ◽  
Mohammad Shalbaf ◽  
Nicholas C. J. Gibbons ◽  
Bhaven Chavan ◽  
J. M. Thornton ◽  
...  

2007 ◽  
Vol 214 (3) ◽  
pp. 568-581 ◽  
Author(s):  
Anthony Scimè ◽  
Lili Li ◽  
Gianni Ciavarra ◽  
Peter Whyte

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