The localization, function and applications of the stress response protein Hsp12p in the yeast Saccharomyces cerevisiae

Abstract

Word processed copy.Includes bibliographical references (leaves 117-132).Since 1990, the yeast Saccharomyces cerevisiae small heat shock protein Hsp12p, has continuously appeared in data associated with stress responses in this organism. Hsp12p is expressed abundantly in response to a large variety of different stresses, but for many years has eluded researchers as to its function, primarily because the viability of yeast strains lacking HSP12 are unaffected by osmotic stress and heat shock. Subsequent studies indicated that Hsp12p played a role in the adaptation of the cell wall of Saccharomyces cerevisiae to conditions of stress. However, the exact in vivo localization, specific function and mediation of function of Hsp12p had yet to be elucidated. The localization of Hsp12p was determined by fusion to the green fluorescent reporter protein, Gfp2p and a combination of epifluorescent microscopy and confocal imagery. Chemical extraction revealed that Hsp12p was present in the cell wall while fluorescent imagery was not conclusive. This fluorescent Hsp12p construct was later employed in a novel application to sense the stress status of yeast, which bears future promise for use in an industrial setting