Redox regulation of cyclophilin A by glutathionylation.
Using redox proteomics techniques to characterize the thiol status of proteins in human T lymphocytes, we identified cyclophilin A (CypA) as a specifically oxidized protein early after mitogen activation. CypA is an abundantly expressed cytosolic protein, target of the immunosuppressive drug cyclosporin A (CsA), for which a variety of functions has been described. In this study, we could identify CypA as a protein undergoing glutathionylation in vivo. Using MALDI-MS we identified Cys52 and Cys62 as targets of glutathionylation in T lymphocytes, and, using bioinformatic tools, we defined the reasons for the susceptibility of these residues to the modification. In addition, we found by circular dichroism spectroscopy that glutathionylation has an important impact on the secondary structure of CypA. Finally, we suggest that glutathionylation of CypA may have biological implications and that CypA may play a key role in redox regulation of immunity.
Ghezzi
Pietro
P
Mario Negri Institute for Pharmacological Research, Milan, Italy.
Casagrande
Simona
S
Massignan
Tania
T
Basso
Manuela
M
Bellacchio
Emanuele
E
Mollica
Luca
L
Biasini
Emiliano
E
Tonelli
Rossella
R
Eberini
Ivano
I
Gianazza
Elisabetta
E
Dai
Wei Wei
WW
Fratelli
Maddalena
M
Salmona
Mario
M
Sherry
Barbara
B
Bonetto
Valentina
V
D002942:Circular Dichroism; D019295:Computational Biology; D021984:Cyclophilin A / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D010084:Oxidation-Reduction; D040901:Proteomics; D011994:Recombinant Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013601:T-Lymphocytes / Q000378:metabolism
D011994:Recombinant Proteins; D021984:Cyclophilin A; D005978:Glutathione; D003545:Cysteine