title: Functional characterization of starvation-induced lysosomal activity in Saccharomyces cerevisiae.
abstract: Starvation induces significant alterations in lysosomal enzymes, and reduced concentrations of glucose increases the activity of several lysosomal enzymes. Therefore, to evaluate the lysosomal antimicrobial activity under starvation conditions, we added 0, 5, 10, 20, or 40 g/l of glucose (0%, 0.5%, 1%, 2%, or 4% glucose) supplemented YP medium to cultured Saccharomyces cerevisiae, and lysosomal fractions were isolated from S. cerevisiae grown under the various culture conditions. The lysosomes isolated from each condition exhibited increased antimicrobial activity against Escherichia coli as determined by a decrease in glucose concentration. In addition, a starvation-dependent increase in lysosomal activity coincided with increased lysosome intensity at the cytosol and distinct protein expression from lysosomes in S. cerevisiae. It also was determined found that the lysosomes have antimicrobial activity against seven different microorganisms, including E. coli, and starvation-induced lysosomes showed enhanced antimicrobial activity compared to those from normal lysosomes. These results suggest the possibility that lysosomal alterations during starvation may induce conditions that activate lysosomes for future development of efficient antimicrobial agents.
authors.affiliation: Graduate School of Semiconductor and Chemical Engineering, Chonbuk National University, 664-14 Duckjin-dong, Jeonju, 561-756, South Korea.
authors.forename: Jihee
authors.initials: J
authors.lastname: Yoon
authors.forename: Suk-Tai
authors.initials: ST
authors.lastname: Chang
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Park
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Jiho
authors.initials: J
authors.lastname: Min
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D008247:Lysosomes / Q000201:enzymology / Q000378:metabolism*; D050296:Microbial Viability / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D005947:Glucose