scholarly journals Self-organization, entropy and allostery

2018 ◽  
Vol 46 (3) ◽  
pp. 587-597 ◽  
Author(s):  
Alexandr P. Kornev
Keyword(s):  
Protein Folding ◽  
Molecular Recognition ◽  
Molecular Mechanism ◽  
Broad Spectrum ◽  
Regulatory Mechanism ◽  
Signal Transmission ◽  
Self Organization ◽  
Common Root ◽  
The Cross ◽  
Polypeptide Chains

Allostery is a fundamental regulatory mechanism in biology. Although generally accepted that it is a dynamics-driven process, the exact molecular mechanism of allosteric signal transmission is hotly debated. We argue that allostery is as a part of a bigger picture that also includes fractal-like properties of protein interior, hierarchical protein folding and entropy-driven molecular recognition. Although so far all these phenomena were studied separately, they stem from the same common root: self-organization of polypeptide chains and, thus, has to be studied collectively. This merge will allow the cross-referencing of a broad spectrum of multi-disciplinary data facilitating progress in all these fields.

scholarly journals Molecular Mechanism of Protein Folding in the Cell

Cell ◽  
2011 ◽  
Vol 146 (6) ◽  
pp. 851-854 ◽  
Author(s):  
James E. Rothman ◽  
Randy Schekman
Keyword(s):  
Protein Folding ◽  
Molecular Mechanism

Principles of chaperone-mediated protein folding

1995 ◽  
Vol 348 (1323) ◽  
pp. 107-112 ◽  
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Cellular Protein ◽  
Chaperone Proteins ◽  
Shock Proteins ◽  
Polypeptide Chains

The recent discovery of molecular chaperones and their functions has changed dramatically our view of the processes underlying the folding of proteins in vivo . Rather than folding spontaneously, most newly synthesized polypeptide chains seem to acquire their native conformations in a reaction mediated by chaperone proteins. Different classes of molecular chaperones, such as the members of the Hsp70 and Hsp60 families of heat-shock proteins, cooperate in a coordinated pathway of cellular protein folding.

scholarly journals Regulatory Mechanism of MicroRNA Expression in Cancer

2020 ◽  
Vol 21 (5) ◽  
pp. 1723 ◽  
Author(s):  
Zainab Ali Syeda ◽  
Siu Semar Saratu’ Langden ◽  
Choijamts Munkhzul ◽  
Mihye Lee ◽  
Su Jung Song
Keyword(s):  
Molecular Mechanism ◽  
Mirna Expression ◽  
Messenger Rna ◽  
Target Genes ◽  
Regulatory Mechanism ◽  
Physiological Role ◽  
Mirna Biogenesis ◽  
Transcriptional Level ◽  
Detailed Knowledge ◽  
Cancer Pathogenesis

Altered gene expression is the primary molecular mechanism responsible for the pathological processes of human diseases, including cancer. MicroRNAs (miRNAs) are virtually involved at the post-transcriptional level and bind to 3′ UTR of their target messenger RNA (mRNA) to suppress expression. Dysfunction of miRNAs disturbs expression of oncogenic or tumor-suppressive target genes, which is implicated in cancer pathogenesis. As such, a large number of miRNAs have been found to be downregulated or upregulated in human cancers and to function as oncomiRs or oncosuppressor miRs. Notably, the molecular mechanism underlying the dysregulation of miRNA expression in cancer has been recently uncovered. The genetic deletion or amplification and epigenetic methylation of miRNA genomic loci and the transcription factor-mediated regulation of primary miRNA often alter the landscape of miRNA expression in cancer. Dysregulation of the multiple processing steps in mature miRNA biogenesis can also cause alterations in miRNA expression in cancer. Detailed knowledge of the regulatory mechanism of miRNAs in cancer is essential for understanding its physiological role and the implications of cancer-associated dysfunction and dysregulation. In this review, we elucidate how miRNA expression is deregulated in cancer, paying particular attention to the cancer-associated transcriptional and post-transcriptional factors that execute miRNA programs.

scholarly journals Inhibition of Transferrin Recycling and Endosome Tubulation by Phospholipase A2Antagonists

2001 ◽  
Vol 276 (50) ◽  
pp. 47361-47370 ◽  
Author(s):  
Paul de Figueiredo ◽  
Anne Doody ◽  
Renée S. Polizotto ◽  
Daniel Drecktrah ◽  
Salli Wood ◽  
...  
Keyword(s):  
Cell Surface ◽  
Molecular Mechanism ◽  
Golgi Complex ◽  
Broad Spectrum ◽  
Tubule Formation ◽  
Recycling Endosomes ◽  
Low Concentrations ◽  
A Cell ◽  
Recycling Pathway ◽  
Lines Of Evidence

We report here that a broad spectrum of phospholipase A2(PLA2) antagonists produce a concentration-dependent, differential block in the endocytic recycling pathway of transferrin (Tf) and Tf receptors (TfRs) but have no acute affect on Tf uptake from the cell surface. At low concentrations of antagonists (∼1 μm), Tf and TfR accumulated in centrally located recycling endosomes, whereas at higher concentrations (∼10 μm), Tf-TfR accumulated in peripheral sorting endosomes. Several independent lines of evidence suggest that this inhibition of recycling may result from the inhibition of tubule formation. First, BFA-stimulated endosome tubule formation was similarly inhibited by PLA2antagonists. Second, endocytosed tracers were found in larger spherical endosomes in the presence of PLA2antagonists. And third, endosome tubule formation in a cell-free, cytosol-dependent reconstitution system was equally sensitive PLA2antagonists. These results are consistent with the conclusion that endosome membrane tubules are formed by the action of a cytoplasmic PLA2and that PLA2-dependent tubules are involved in intracellular recycling of Tf and TfR. When taken together with previous studies on the Golgi complex, these results also indicate that an intracellular PLA2activity provides a novel molecular mechanism for inducing tubule formation from multiple organelles.

Sign in / Sign up

Export Citation Format

Share Document