title: Novel IEF Peptide Fractionation Method Reveals a Detailed Profile of N-Terminal Acetylation in Chemotherapy-Responsive and -Resistant Ovarian Cancer Cells.
abstract: Although acetylation is regarded as a common protein modification, a detailed proteome-wide profile of this post-translational modification may reveal important biological insight regarding differential acetylation of individual proteins. Here we optimized a novel peptide IEF fractionation method for use prior to LC-MS/MS analysis to obtain a more in depth coverage of N-terminally acetylated proteins from complex samples. Application of the method to the analysis of the serous ovarian cancer cell line OVCAR-5 identified 344 N-terminally acetylated proteins, 12 of which are previously unreported. The protein peptidyl-prolyl cis-trans isomerase A (PPIA) was detected in both the N-terminally acetylated and unmodified forms and was further analyzed by data-independent acquisition in carboplatin-responsive parental OVCAR-5 cells and carboplatin-resistant OVCAR-5 cells. This revealed a higher ratio of unacetylated to acetylated N-terminal PPIA in the parental compared with the carboplatin-resistant OVCAR-5 cells and a 4.1-fold increase in PPIA abundance overall in the parental cells relative to carboplatin-resistant OVCAR-5 cells (P = 0.015). In summary, the novel IEF peptide fractionation method presented here is robust, reproducible, and can be applied to the profiling of N-terminally acetylated proteins. All mass spectrometry data is available as a ProteomeXchange repository (PXD003547).
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|The Institute for Photonics & Advanced Sensing (IPAS), The University of Adelaide , Adelaide, South Australia 5005, Australia.
authors: Florian
authors: F
authors: Weiland
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|The Institute for Photonics & Advanced Sensing (IPAS), The University of Adelaide , Adelaide, South Australia 5005, Australia.
authors: Georgia
authors: G
authors: Arentz
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|The Institute for Photonics & Advanced Sensing (IPAS), The University of Adelaide , Adelaide, South Australia 5005, Australia.
authors: Manuela
authors: M
authors: Klingler-Hoffmann
authors: Department of Human Immunology, Centre for Cancer Biology, University of South Australia , Adelaide, South Australia 5000, Australia.
authors: Peter
authors: P
authors: McCarthy
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|Robinson Institute, Research Centre for Reproductive Health, School of Paediatrics and Reproductive Health, University of Adelaide , Adelaide, South Australia 5005, Australia.
authors: Noor A
authors: NA
authors: Lokman
authors: Institute for Research in Molecular Medicine, Universiti Sains Malaysia , 11800 Minden, Pulau Pinang, Malaysia.
authors: Gurjeet
authors: G
authors: Kaur
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|Robinson Institute, Research Centre for Reproductive Health, School of Paediatrics and Reproductive Health, University of Adelaide , Adelaide, South Australia 5005, Australia.|Department of Gynaecological Oncology, Royal Adelaide Hospital , Adelaide, South Australia 5005, Australia.
authors: Martin K
authors: MK
authors: Oehler
authors: Adelaide Proteomics Centre, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.|The Institute for Photonics & Advanced Sensing (IPAS), The University of Adelaide , Adelaide, South Australia 5005, Australia.
authors: Peter
authors: P
authors: Hoffmann
mesh_terms: D000107:Acetylation; D000970:Antineoplastic Agents / Q000494:pharmacology; D016190:Carboplatin / Q000494:pharmacology; D045744:Cell Line, Tumor; D005591:Chemical Fractionation / Q000379:methods; D030562:Databases, Protein; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D013058:Mass Spectrometry; D010051:Ovarian Neoplasms / Q000188:drug therapy*; D010446:Peptide Fragments / Q000032:analysis*; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods
chemical_list: D000970:Antineoplastic Agents; D010446:Peptide Fragments; D016190:Carboplatin
keywords: N-terminal acetylation; PPIA; carboplatin resistance; chemoresistance; ovarian cancer; peptidyl-prolyl cis−trans isomerase A