ABSTRACT
【Objective】 To explore the potential biomarkers and related enrichment pathways of dilated cardiomyopathy （DCM） by bioinformatics methods. 【Methods】 The data sets related to DCM in GEO database were searched， and microarray data sets GSE42955 and GSE1869 of human cardiomyocytes were extracted. Then， the differentially expressed genes （DEGS） were analyzed using R language， and the protein-protein interaction network was analyzed to identify the core genes and core modules of differential expression. The gene ontology database （GO） enrichment and Kyoto Gene and Genome Encyclopedia （KEGG） pathway analyses were performed. The data sets related to DCM in ArrayExpress database were searched， and the human cardiomyocytes microarray data set E-TABM-480 was extracted to verify the expressions of core genes and modules. 【Results】 We identified 10 DEGS， namely， DZIP3， FBXO32， BTBD6， FBXL5， ASB8， COMMD1， LTN1， FBXO21， RCHY1 and ARIH2， and the core DEG was DZIP3. After GO and KEGG analyses， the GO and KEGG of the above DEGS were mainly related to the ubiquitin-proteasome system. 【Conclusion】 Bioinformatics analysis shows that the ubiquitin-proteasome system plays an important role in the pathogenesis of DCM， and the mechanism remains to be further studied.
ABSTRACT
Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
ABSTRACT
Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
ABSTRACT
Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
ABSTRACT
Ubiquitin, a small eukaryotic protein serving as a post-translational modification on many important proteins, plays central role in cellular homeostasis and cell cycle regulation. Ubiquitin features two -bulges, the second -bulge, located at the C-terminal region of the protein along with type II turn, holds 3 residues Glu64(1), Ser65(2) and Gln2(X). Percent frequency of occurrence of such a sequence in parallel -bulge is very low. However, the sequence and structure have been conserved in ubiquitin through out the evolution. Present study involves replacement of residues in unusual -bulge of ubiquitin by introducing mutations in combination through site directed mutagenesis, generating double and triple mutants and their functional characterization. Mutant ubiquitins cloned in yeast expression vector YEp96 tested for growth profile, viability assay and heat stress complementation study have revealed significant decrease in growth rate, loss of viability and non-complementation of heat sensitive phenotype with UbE64G-S65D and UbQ2N-E64G-S65D mutations. However, UbQ2N-S65D did not show any negative effects in the above assays. Present results show that, replacement of residues in -bulge of ubiquitin exerts severe effects on growth and viability in Saccharomyces cerevisiae due to functional failure of the mutant ubiquitins UbE64G-S65D and UbQ2N-E64G-S65D.