Functional proteomics of transforming growth factor-beta1-stimulated Mv1Lu epithelial cells: Rad51 as a target of TGFbeta1-dependent regulation of DNA repair.
Transforming growth factor-beta (TGFbeta) conveys regulatory signals through multiple intracellular pathways, subsequently affecting various cellular functions. To identify new targets for TGFbeta, we studied the changes in the proteome of Mv1Lu lung epithelial cells in response to TGFbeta1 treatment. Thirty-eight non-abundant protein spots, affected by TGFbeta1, were selected, and proteins were identified by peptide mass-fingerprinting (PMF). Among them, proteins involved in regulation of immune response, apoptosis, regulation of TGFbeta signalling, metabolism and DNA repair were identified. Twenty-eight of the 38 proteins are new targets for TGFbeta1, thus suggesting novel ways of integration of TGFbeta signalling in intracellular regulatory processes. We show that TGFbeta1-dependent decrease in expression of one of the new targets, Rad51, correlates with a decrease in DNA repair efficiency. This was evaluated by formation of nuclear Rad51-containing DNA repair complexes in response to DNA damage, by single cell gel electrophoresis and by cell survival assay. The TGFbeta1-dependent inhibition of DNA repair was reversed by ectopic overexpression of Rad51. Therefore, TGFbeta can promote DNA instability through down-regulation of Rad51 and inhibition of DNA repair.
Kanamoto
Takashi
T
Ludwig Institute for Cancer Research, Box 595, SE-751 24, Uppsala, Sweden.
Hellman
Ulf
U
Heldin
Carl-Henrik
CH
Souchelnytskyi
Serhiy
S
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001943:Breast Neoplasms / Q000473:pathology; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002460:Cell Line / Q000187:drug effects / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000096:biosynthesis / Q000235:genetics; D004260:DNA Repair / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D004847:Epithelial Cells / Q000187:drug effects; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007525:Isoelectric Focusing; D008168:Lung / Q000166:cytology*; D051379:Mice; D008907:Mink; D010449:Peptide Mapping; D020543:Proteome; D051135:Rad51 Recombinase; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D051899:Smad2 Protein; D051900:Smad3 Protein; D015534:Trans-Activators / Q000172:deficiency; D014158:Transcription, Genetic / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D020543:Proteome; D011993:Recombinant Fusion Proteins; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; C497783:Smad2 protein, mouse; D051900:Smad3 Protein; C497791:Smad3 protein, mouse; C508960:TGFB1 protein, human; C508961:Tgfb1 protein, mouse; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C495154:Rad51 protein, mouse