Hsp12 of is one of the most prominent proteins of the yeast stress response. As indicated by the graphical schemes (top) and scanning electron micrographs (bottom), Hsp12 is needed to stabilize the plasma membrane at stress conditions (left). Its absence leads to altered cell morphology and changes in membrane fluidity and stability.
In the Aug. 27, 2010, issue of Molecular Cell, Welker et al. describe the cellular survival mechanism that Hsp12 provides, which they say defines an entirely new class of stress proteins. Normally unfolded within the yeast cell's aqueous cytosol, Hsp12 folds into helical structures to stabilize the cell membrane against heat shock and other kinds of stress.