title: Proteomic and Metabolic Analyses of S49 Lymphoma Cells Reveal Novel Regulation of Mitochondria by cAMP and Protein Kinase A.
abstract: Cyclic AMP (cAMP), acting via protein kinase A (PKA), regulates many cellular responses, but the role of mitochondria in such responses is poorly understood. To define such roles, we used quantitative proteomic analysis of mitochondria-enriched fractions and performed functional and morphologic studies of wild-type (WT) and kin(-) (PKA-null) murine S49 lymphoma cells. Basally, 75 proteins significantly differed in abundance between WT and kin(-) S49 cells. WT, but not kin(-), S49 cells incubated with the cAMP analog 8-(4-chlorophenylthio)adenosine cAMP (CPT-cAMP) for 16 h have (a) increased expression of mitochondria-related genes and proteins, including ones in pathways of branched-chain amino acid and fatty acid metabolism and (b) increased maximal capacity of respiration on branched-chain keto acids and fatty acids. CPT-cAMP also regulates the cellular rate of ATP-utilization, as the rates of both ATP-linked respiration and proton efflux are decreased in WT but not kin(-) cells. CPT-cAMP protected WT S49 cells from glucose or glutamine deprivation, In contrast, CPT-cAMP did not protect kin(-) cells or WT cells treated with the PKA inhibitor H89 from glutamine deprivation. Under basal conditions, the mitochondrial structure of WT and kin(-) S49 cells is similar. Treatment with CPT-cAMP produced apoptotic changes (i.e. decreased mitochondrial density and size and loss of cristae) in WT, but not kin(-) cells. Together, these findings show that cAMP acts via PKA to regulate multiple aspects of mitochondrial function and structure. Mitochondrial perturbation thus likely contributes to cAMP/PKA-mediated cellular responses.
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626.
authors.forename: Andrea
authors.initials: A
authors.lastname: Wilderman
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0654.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626.
authors.forename: Ajit S
authors.initials: AS
authors.lastname: Divakaruni
authors.affiliation: National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, California 92093-0608, and.
authors.forename: Guy
authors.initials: G
authors.lastname: Perkins
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626.
authors.forename: Lingzhi
authors.initials: L
authors.lastname: Zhang
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626.
authors.forename: Anne N
authors.initials: AN
authors.lastname: Murphy
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626, Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0654.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Taylor
authors.affiliation: From the Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0626, Department of Medicine, University of California San Diego, La Jolla, California 92093 pinsel@ucsd.edu.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Insel
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001343:Autophagy / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D015151:Immunoblotting; D016399:Lymphoma, T-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008854:Microscopy, Electron; D008928:Mitochondria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D040901:Proteomics / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D013873:Thionucleotides; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases
keywords: cell metabolism; cyclic AMP (cAMP); mitochondria; protein kinase A (PKA); proteomics