The role of K(+) and H(+) transport systems during glucose- and H(2)O(2)-induced cell death in Saccharomyces cerevisiae.
Glucose, in the absence of additional nutrients, induces programmed cell death in yeast. This phenomenon is independent of yeast metacaspase (Mca1/Yca1) and of calcineurin, requires ROS production and it is concomitant with loss of cellular K(+) and vacuolar collapse. K(+) is a key nutrient protecting the cells and this effect depends on the Trk1 uptake system and is associated with reduced ROS production. Mutants with decreased activity of plasma membrane H(+)-ATPase are more tolerant to glucose-induced cell death and exhibit less ROS production. A triple mutant ena1-4 tok1 nha1, devoid of K(+) efflux systems, is more tolerant to both glucose- and H(2)O(2)-induced cell death. We hypothesize that ROS production, activated by glucose and H(+)-ATPase and inhibited by K(+) uptake, triggers leakage of K(+), a process favoured by K(+) efflux systems. Loss of cytosolic K(+) probably causes osmotic lysis of vacuoles. The nature of the ROS-producing system sensitive to K(+) and H(+) transport is unknown.
Hoeberichts
Frank A
FA
Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia--CSIC, Spain.
Perez-Valle
Jorge
J
Montesinos
Consuelo
C
Mulet
José M
JM
Planes
María D
MD
Hueso
Guillem
G
Yenush
Lynne
L
Sharma
Sukesh C
SC
Serrano
Ramón
R
D027682:Cation Transport Proteins / Q000378:metabolism; D016923:Cell Death; D005947:Glucose / Q000633:toxicity*; D017506:H(+)-K(+)-Exchanging ATPase / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000633:toxicity*; D009997:Osmotic Pressure; D011188:Potassium / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000633:toxicity; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D027682:Cation Transport Proteins; D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; C068664:TRK1 protein, S cerevisiae; D006859:Hydrogen; D006861:Hydrogen Peroxide; D017506:H(+)-K(+)-Exchanging ATPase; D005947:Glucose; D011188:Potassium