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Biomedical subjects

R John Ellis

Publications and source records attributed to R John Ellis.

12 recordsLinked to original sources
PubMed2007

Protein misassembly: macromolecular crowding and molecular chaperones.

The generic tendency of proteins to misassemble into nonfunctional, and sometimes cytotoxic, structures poses a universal problem for all types of cell. This problem is exacerbated by the high total concentration of macromolecules found within most intracellular compartments but it is solved by the actions of molecular chaperones. This review discusses some of the basic evidence and key concepts relating to this conclusion.

Animals↗
PubMed2006

Molecular chaperones: assisting assembly in addition to folding.

The common perception that molecular chaperones are involved primarily with assisting the folding of newly synthesized and stress-denatured polypeptide chains ignores the fact that this term was invented to describe the function of a protein that assists the assembly of folded subunits into oligomeric structures and only later was extended to embrace protein folding. Recent work has clarified the role of nuclear chaperones in the assembly of nucleosomes and has identified a cytosolic chaperone required for mammalian proteasome assembly, suggesting that the formation of other oligomeric complexes might be assisted by chaperones.

Animals↗
PubMed2006

Protein aggregation in crowded environments.

The generic tendency of proteins to aggregate into non-functional, and sometimes cytotoxic, structures poses a universal problem for all types of cell. This tendency is greatly exacerbated by the high total concentration of macromolecules found within most intracellular compartments, a phenomenon referred to as macromolecular crowding. This review discusses the quantitative effects of crowding on protein aggregation and the role of molecular chaperones in combating this problem.

Algorithms↗
PubMed2005

Chaperomics: in vivo GroEL function defined.

A recent proteome analysis of protein folding inside cells of Escherichia coli predicts that only 84 of the approximately 2400 cytosolic proteins expressed in minimal media depend absolutely on the GroEL/GroES chaperone system to avoid aggregation. These proteins are enriched in alpha/beta domains and 13 are essential for growth.

Bacterial Proteins↗
PubMed2004

From chloroplasts to chaperones: how one thing led to another.

Two lessons I have learned during my research career are the importance of following up unexpected observations and realizing that the most obvious interpretation of such observations can be rational but wrong. When you carry out an experiment there is usually an expectation that the result will fall within a range of predictable outcomes, and it is natural to feel pleased when this turns out to be the case. In my view this response is a mistake. What you should be hoping for is a puzzling result that was not anticipated since with persistence and luck further experiments may uncover something new. In this article I give a personal account of how studies of the synthesis of proteins by isolated intact chloroplasts from pea leaves eventually led to the discovery of the chaperonins and the formulation of the general concept of the molecular chaperone function that is now seen to be a fundamental aspect of how all cells work.

Journal Article↗