p53 Affects Zeb1 Interactome of Breast Cancer Stem Cells.

P53 is a critical tumor suppressor that protects the integrity of genome and prevents cells from malignant transformation, including metastases. One of the driving forces behind the onset of metastases is the epithelial to mesenchymal transition (EMT) program. Zeb1 is one of the key transcription factors that govern EMT (TF-EMT).

Proteomic Analysis of Zeb1 Interactome in Breast Carcinoma Cells.

Breast cancer is the most frequently diagnosed malignant neoplasm and the second leading cause of cancer death among women. Epithelial-to-mesenchymal Transition (EMT) plays a critical role in the organism development, providing cell migration and tissue formation. However, its erroneous activation in malignancies can serve as the basis for the dissemination of cancer cells and metastasis.

The Long Linker Region of Telomere-Binding Protein TRF2 Is Responsible for Interactions with Lamins.

Telomere-binding factor 2 (TRF2) is part of the shelterin protein complex found at chromosome ends. Lamin A/C interacts with TRF2 and influences telomere position. TRF2 has an intrinsically disordered region between the ordered dimerization and DNA-binding domains.

Proteomics Answers Which Yeast Genes Are Specific for Baking, Brewing, and Ethanol Production.

Yeast strains are convenient models for studying domestication processes. The ability of yeast to ferment carbon sources from various substrates and to produce ethanol and carbon dioxide is the core of brewing, winemaking, and ethanol production technologies. The present study reveals the differences among yeast strains used in various industries.

Proteomic Profiling of the Human Fetal Multipotent Mesenchymal Stromal Cells Secretome.

Secretome of multipotent mesenchymal stromal cells (MSCs) is actively used in biomedical applications such as alveolar bone regeneration, treatment of cardiovascular disease, and neurodegenerative disorders. Nevertheless, hMSCs have low proliferative potential and production of the industrial quantity of their secretome might be challenging. Human fetal multipotent mesenchymal stromal cells (FetMSCs) isolated from early human embryo bone marrow are easy to expand and might be a potential source for pharmaceutical substances production based on their secretome.

Combined treatment of human multiple myeloma cells with bortezomib and doxorubicin alters the interactome of 20S proteasomes.

Unlabelled: The proteasome is the key player in targeted degradation of cellular proteins and serves as a therapeutic target for treating several blood malignancies. Although in general, degradation of proteins via the proteasome requires their ubiquitination, a subset of proteins can be degraded independently of their ubiquitination by direct interaction with subunits of the 20S proteasome core. Thus, investigation of the proteasome-associated proteins may help identify novel targets of proteasome degradation and provide important insights into the mechanisms of malignant cell proteostasis.

Co-expression of RelA/p65 and ACTN4 induces apoptosis in non-small lung carcinoma cells.

Alpha-actinin 4 (ACTN4) is an actin-binding protein of the spectrin superfamily. ACTN4 is found both in the cytoplasm and nucleus of eukaryotic cells. The main function of cytoplasmic ACTN4 is stabilization of actin filaments and their binding to focal contacts.

Regulation of Endoribonuclease Activity of Alpha-Type Proteasome Subunits in Proerythroleukemia K562 Upon Hemin-Induced Differentiation.

The proteasome is the main intracellular proteolytic machine involved in the regulation of numerous cellular processes, including gene expression. In addition to their proteolytic activity, proteasomes also exhibit ATPase/helicase (the 19S particle) and RNAse (the 20S particle) activities, which are regulated by post-translational modifications. In this report we uncovered that several 20S particle subunits: α1 (PSMA6), α2 (PSMA2), α4 (PSMA7), α5 (PSMA5), α6 (PSMA1) and α7 (PSMA3) possess RNAse activity against the p53 mRNA in vitro.

The effect of red pigment on the amyloidization of yeast proteins.

The intensity of amyloid-bound thioflavine T fluorescence was studied in crude lysates of yeast strains carrying mutations in the ADE1 or ADE2 genes and accumulating the red pigment (a result of polymerization of aminoimidazoleribotide), and in white isogenic strains--either adenine prototrophs or carrying mutations at the first stages of purine biosynthesis. We found that the red pigment leads to a drop of amyloid content. This result, along with the data on separation of protein polymers of white and red strains in PAGE, suggests that the red pigment inhibits amyloid fibril formation.

26S proteasome exhibits endoribonuclease activity controlled by extra-cellular stimuli.

26S proteasome is a large multi-subunit protein complex involved in proteolytic degradation of proteins. In addition to its canonical proteolytic activity, the proteasome is also associated with recently characterized endoribonuclease (endo- RNAse) activity. However, neither functional significance, nor the mechanisms of its regulation are currently known.

Prion-associated proteins in yeast: comparative analysis of isogenic [PSI(+)] and [psi(-)] strains.

A large group of prion-associated proteins was identified in yeast cells using a new approach, comparative analysis of pellet proteins of crude cell lysates in isogenic strains of Saccharomyces cerevisiae differing by their prion composition. Two-dimensional (2D) electrophoresis followed by MALDI analysis of the pellet proteins of [PSI(+)] and [psi(-)] strains after prion elimination by GuHCl and prion transmission by cytoduction permitted identification of ca. 40 proteins whose aggregation state correlated with the change of prion(s) content.

Role of proteasomes in cellular regulation.

The 26S proteasome is the key enzyme of the ubiquitin-dependent pathway of protein degradation. This energy-dependent nanomachine is composed of a 20S catalytic core and associated regulatory complexes. The eukaryotic 20S proteasomes demonstrate besides several kinds of peptidase activities, the endoribonuclease, protein-chaperone and DNA-helicase activities.

Role of proteasomes in transcription and their regulation by covalent modifications.

The 26S proteasome is an abundant multi-subunit complex, which, in addition to lysosomes, represents a major cellular "protein degradation factory". The proteasome complex possesses protease, ATPase/helicase, and RNAse enzymatic activities, which are used by the latter to regulate various physiological processes. Recent findings have revealed an important role of proteasomes in transcriptional regulation.

Changes in composition and activities of 26S proteasomes under the action of doxorubicin--apoptosis inductor of erythroleukemic K562 cells.

Changes in the subunit composition, phosphorylation of the subunits, and regulation of the activities of 26S proteasomes in proliferating cells undergoing programmed cell death have not been studied so far. Moreover, there are no reports on phosphorylation of proteasome subunits both in normal and in neoplastic cells during apoptosis. The data of the present study show for the first time that apoptosis inductor doxorubicin regulates subunit composition, enzymatic activities, and phosphorylation state of 26S proteasomes in neoplastic (proerythroleukemic K562) cells or, in other words, induces reprogramming of proteasome population.