Research identifies a new process for how cells can quickly respond and survive when exposed to cellular stresses

Complex biological organisms, such as humans, are composed of countless numbers of cells of various types. All cells are constantly exposed to internal and external factors that constitute different varieties of stresses that cause damage to important molecular components within the cell. Such molecular components are essential in allowing cells to carry out their biological functions correctly. Unless a cell can rapidly activate its defence mechanisms successfully in response to exposure to different stresses, the cell will not survive. One possible important consequence of cellular malfunction or death is disease. The article titled “Rapid deacetylation of yeast Hsp70 mediates the cellular response to heat stress” was recently published in the journal Scientific Reports and identifies a new process for how cells can quickly respond and survive when exposed to cellular stresses such as heat shock or oxidative stress.

Commenting on the article Professor Jones said “Cells have evolved a variety of tools to survive exposure to stresses such as heat shock. One of the most important survival pathways involves the ability to withstand damage caused to proteins [the ‘workhorses’ of cells]. In humans, when key proteins become damaged or incorrectly fold and lose function, this can cause disease. The most prominent of the so-called protein misfolding diseases are Alzheimer’s and Parkinson’s. A key cellular defence in coping with protein damage is the Hsp70 molecular chaperone system. Hsp70 is a protein that helps to prevent other proteins from becoming misfolded and losing function. Understanding how Hsp70 works at the molecular level within the cell is critical for deciphering the key actions of this protein in enabling other important proteins to function correctly and keeping cells healthy within an organism. The function of proteins can be rapidly altered within cells by the addition of small chemical moieties such as phosphoryl or acetyl groups. A process called post-translational modification (PTM). In this article we use baker’s yeast, a well characterised model organism for such studies, and identify four amino acid residues within the Hsp70 protein that undergo PTM changes in response to exposure to heat stress. The PTMs that occur allow Hsp70 to maintain its function in the presence of heat stress and improve cell survival. This work therefore provides new insight into the importance of PTM on the functionality of Hsp70 and how this protein responds upon exposure to cellular stress”.

This work is an international collaboration effort with contributions from the laboratories of Professor Andrew Truman [University of North Carolina Charlotte, USA], Professor Sarah Perrett [Chinese Academy of Sciences, Beijing, China] and researchers at Maynooth University in Ireland. Other publications from the group include the seminal publication in the world-leading biochemistry & molecular biology journal CELL, which for the first time, identified and characterised the functional outcome of PTM in Hsp70 in vivo, and recent publications in the Journal of Biological Chemistry and Cellular & Molecular Life Sciences, that help define key elements of how the peptide-binding and C-terminal domains of Hsp70 contribute to its function. Two recent invited minireviews from the group on Hsp70 function can be found in Current Genetics and Prion.