Search results for "Eukaryotic cells"
showing 10 items of 27 documents
Probes for studying cholesterol binding and cell biology.
2011
Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…
Evaluation of acyl coenzyme A oxidase (Aox) isozyme function in the n- alkane-assimilating yeast Yarrowia lipolytica
1999
ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n -alkane-assimilating yeast Yarrowia lipolytica , encoded by the POX1 through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to …
Heat shock and Cd2+ exposure regulate PML and Daxx release from ND10 by independent mechanisms that modify the induction of heat-shock proteins 70 an…
2003
Nuclear domains called ND10 or PML bodies might function as nuclear depots by recruiting or releasing certain proteins. Although recruitment of proteins through interferon-induced upregulation and SUMO-1 modification level of PML had been defined, it is not known whether release of proteins is regulated and has physiological consequences. Exposure to sublethal environmental stress revealed a sequential release of ND10-associated proteins. Upon heat shock Daxx and Sp100 were released but PML remained, whereas exposure to subtoxic concentrations of CdCl2 induced the release of ND10-associated proteins, including PML, with Sp100 remaining in a few sites. In both cases,recovery times were simil…
Evolutionary conserved role of eukaryotic translation factor eIF5A in the regulation of actin-nucleating formins
2017
AbstractElongation factor eIF5A is required for the translation of consecutive prolines, and was shown in yeast to translate polyproline-containing Bni1, an actin-nucleating formin required for polarized growth during mating. Here we show that Drosophila eIF5A can functionally replace yeast eIF5A and is required for actin-rich cable assembly during embryonic dorsal closure (DC). Furthermore, Diaphanous, the formin involved in actin dynamics during DC, is regulated by and mediates eIF5A effects. Finally, eIF5A controls cell migration and regulates Diaphanous levels also in mammalian cells. Our results uncover an evolutionary conserved role of eIF5A regulating cytoskeleton-dependent processes…
Pterostilbene-induced tumor cytotoxicity: a lysosomal membrane permeabilization-dependent mechanism.
2012
The phenolic phytoalexin resveratrol is well known for its health-promoting and anticancer properties. Its potential benefits are, however, limited due to its low bioavailability. Pterostilbene, a natural dimethoxylated analog of resveratrol, presents higher anticancer activity than resveratrol. The mechanisms by which this polyphenol acts against cancer cells are, however, unclear. Here, we show that pterostilbene effectively inhibits cancer cell growth and stimulates apoptosis and autophagosome accumulation in cancer cells of various origins. However, these mechanisms are not determinant in cell demise. Pterostilbene promotes cancer cell death via a mechanism involving lysosomal membrane …
Synthetic biomolecular condensates to engineer eukaryotic cells
2021
Abstract The compartmentalization of specific functions into specialized organelles is a key feature of eukaryotic life. In particular, dynamic biomolecular condensates that are not membrane enclosed offer exciting opportunities for synthetic biology. In recent years, multiple approaches to generate and control condensates have been reported. Notably, multiple orthogonally translating organelles were designed that enable precise protein engineering inside living cells. Despite being built from only very few components, orthogonal translation can be engineered with subresolution precision at different places inside the same cell to create mammalian cells with multiple expanded genetic codes.…
Cytotoxic Action of Serratia marcescens Hemolysin on Human Epithelial Cells
1999
ABSTRACT Incubation of human epithelial cells with nanomolar concentrations of chromatographically purified Serratia marcescens hemolysin (ShlA) caused irreversible vacuolation and subsequent lysis of the cells. Vacuolation differed from vacuole formation by Helicobacter pylori VacA. Sublytic doses of ShlA led to a reversible depletion of intracellular ATP. Restoration to the initial ATP level was presumably due to the repair of the toxin damage and was inhibited by cycloheximide. Pores formed in epithelial cells and fibroblasts without disruption of the plasma membrane, and the pores appeared to be considerably smaller than those observed in artificial lipid membranes and in erythrocytes a…
The introduction of fluorine atoms or trifluoromethyl groups in short cationic peptides enhances their antimicrobial activity
2006
The effect of introducing fluorine atoms or trifluoromethyl groups in either the peptidic chain or the C-terminal end of cationic pentapeptides is reported. Three series of amide and ester peptides were synthesised and their antimicrobial properties evaluated. An enhanced activity was found in those derivatives whose structure contained fluorine, suggesting an increase in their hydrophobicity.
Dual film-like organelles enable spatial separation of orthogonal eukaryotic translation
2021
Summary Engineering new functionality into living eukaryotic systems by enzyme evolution or de novo protein design is a formidable challenge. Cells do not rely exclusively on DNA-based evolution to generate new functionality but often utilize membrane encapsulation or formation of membraneless organelles to separate distinct molecular processes that execute complex operations. Applying this principle and the concept of two-dimensional phase separation, we develop film-like synthetic organelles that support protein translation on the surfaces of various cellular membranes. These sub-resolution synthetic films provide a path to make functionally distinct enzymes within the same cell. We use t…
STAT Proteins: From Normal Control of Cellular Events to Tumorigenesis
2003
Signal transducers and activators of transcription (STAT) proteins comprise a family of transcription factors latent in the cytoplasm that participate in normal cellular events, such as differentiation, proliferation, cell survival, apoptosis, and angiogenesis following cytokine, growth factor, and hormone signaling. STATs are activated by tyrosine phosphorylation, which is normally a transient and tightly regulates process. Nevertheless, several constitutively activated STATs have been observed in a wide number of human cancer cell lines and primary tumors, including blood malignancies and solid neoplasias. STATs can be divided into two groups according to their specific functions. One is …