A plant defense response effector induces microbial apoptosis.
Osmotin is a tobacco PR-5 protein that has antifungal activity and is implicated in host-plant defense. We show here that osmotin induces apoptosis in Saccharomyces cerevisiae. Induction of apoptosis was correlated with intracellular accumulation of reactive oxygen species and was mediated by RAS2, but not RAS1. Osmotin treatment resulted in suppression of transcription of stress-responsive genes via the RAS2/cAMP pathway. It was therefore concluded that osmotin induced proapoptotic signaling in yeast. The results indicate that the ability of antimicrobial proteins to induce microbial apoptosis could be an important factor in determining a pathogen's virulence and could therefore be targeted for the design of new antifungal drugs.
Narasimhan
M L
ML
Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, IN 47907, USA.
Damsz
B
B
Coca
M A
MA
Ibeas
J I
JI
Yun
D J
DJ
Pardo
J M
JM
Hasegawa
P M
PM
Bressan
R A
RA
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002417:Cattle; D048429:Cell Size / Q000187:drug effects; D003574:Cytochrome c Group / Q000494:pharmacology; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D008954:Models, Biological; D010940:Plant Proteins / Q000494:pharmacology*; D011107:Polylysine / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D018631:ras Proteins / Q000378:metabolism
D003574:Cytochrome c Group; D005656:Fungal Proteins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; C073139:osmotin protein, Nicotiana tabacum; D011107:Polylysine; D012710:Serum Albumin, Bovine; C489014:RAS1 protein, S cerevisiae; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins