Reversible glutathionylation regulates actin polymerization in A431 cells.
In response to growth factor stimulation, many mammalian cells transiently generate reactive oxygen species (ROS) that lead to the elevation of tyrosine-phosphorylated and glutathionylated proteins. While investigating EGF-induced glutathionylation in A431 cells, paradoxically we found deglutathionylation of a major 42-kDa protein identified as actin. Mass spectrometric analysis revealed that the glutathionylation site is Cys-374. Deglutathionylation of the G-actin leads to about a 6-fold increase in the rate of polymerization. In vivo studies revealed a 12% increase in F-actin content 15 min after EGF treatment, and F-actin was found in the cell periphery suggesting that in response to growth factor, actin polymerization in vivo is regulated by a reversible glutathionylation mechanism. Deglutathionylation is most likely catalyzed by glutaredoxin (thioltranferase), because Cd(II), an inhibitor of glutaredoxin, inhibits intracellular actin deglutathionylation at 2 microM comparable with its IC(50) in vitro. Moreover, mass spectral analysis showed efficient transfer of GSH from immobilized S-glutathionylated actin to glutaredoxin. Overall, this study revealed a novel physiological relevance of actin polymerization regulated by reversible glutathionylation of the penultimate cysteine mediated by growth factor stimulation.
Wang
J
J
Laboratory of Biochemistry, NHLBI, National Institutes of Health, Bethesda, Maryland 20892-8012, USA.
Boja
E S
ES
Tan
W
W
Tekle
E
E
Fales
H M
HM
English
S
S
Mieyal
J J
JJ
Chock
P B
PB
D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D001704:Biopolymers / Q000378:metabolism*; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data
D000199:Actins; D001704:Biopolymers; D004815:Epidermal Growth Factor; D005978:Glutathione