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Proteomic analysis of the cAMP/protein kinase A (PKA) signaling pathway identifies PKA as a regulator of cellular response to oxidative stress
Author(s) -
McCann Thalia,
Wilderman Andrea S.,
Guo Yurong,
Taylor Susan S.,
Insel Paul A.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1143.16
Subject(s) - protein kinase a , microbiology and biotechnology , signal transduction , oxidative stress , viability assay , apoptosis , chemistry , protein kinase b , second messenger system , biology , kinase , biochemistry
The second messenger cAMP, acting through PKA, induces apoptosis in certain lymphoma and leukemia cells. This apoptotic response facilitated the isolation of a cAMP‐resistant, clonal variant of wild‐type (WT) murine S49 cells; these cAMP‐resistant cells lack PKA activity (kin‐cells) and expression of the PKA catalytic subunit. As an approach to identify “new” actions of cAMP/PKA, we used a quantitative proteomic (iTRAQ) method and compared the protein expression profiles of WT and kin‐ S49 cells under “basal” conditions. We identified 19 proteins with altered (12 higher, 7 lower) basal expression in kin‐ cells. Among the proteins with higher basal expression in kin‐ cells are the antioxidants glutathione reductase (Gsr) and thioredoxin1 (Txn1). Consistent with this increase in antioxidant expression, we found that, compared to WT cells, kin‐ cells have increased resistance to oxidative stress (150 μM H 2 O 2 for 16 hr), measured as cell viability and lipid peroxidation (the production of malondialdehyde). cAMP/PKA thus inhibits the basal expression of two important antioxidants. The loss of PKA function in kin‐cells may help protect these (and perhaps other) T cells from oxidative damage. More generally, these data reveal the ability of a global proteomic approach to identify new features of cAMP/PKA signaling and regulation in mammalian cells. (Supported by HHMI [SST] and NIH Grants [SST and PAI]).