title: Identification of c-MYC SUMOylation by mass spectrometry.
abstract: The c-MYC transcription factor is a master regulator of many cellular processes and deregulation of this oncogene has been linked to more than 50% of all cancers. This deregulation can take many forms, including altered post-translational regulation. Here, using immunoprecipitation combined with mass spectrometry, we identified a MYC SUMOylation site (K326). Abrogation of signaling through this residue by substitution with arginine (K326R) has no obvious effects on MYC half-life, intracellular localization, transcriptional targets, nor on the biological effects of MYC overexpression in two different cell systems assessed for soft agar colony formation, proliferation, and apoptosis. While we have definitively demonstrated that MYC SUMOylation can occur on K326, future work will be needed to elucidate the mechanisms and biological significance of MYC regulation by SUMOylation.
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Manpreet
authors.initials: M
authors.lastname: Kalkat
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
authors.forename: Pak-Kei
authors.initials: PK
authors.lastname: Chan
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Wasylishen
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
authors.forename: Tharan
authors.initials: T
authors.lastname: Srikumar
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Sam S
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
authors.forename: Romina
authors.initials: R
authors.lastname: Ponzielli
authors.affiliation: Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada.
authors.forename: David P
authors.initials: DP
authors.lastname: Bazett-Jones
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Raught
authors.affiliation: Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Linda Z
authors.initials: LZ
authors.lastname: Penn
mesh_terms: D019943:Amino Acid Substitution; D001120:Arginine / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D061986:MCF-7 Cells; D013058:Mass Spectrometry; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D058207:Sumoylation
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D001120:Arginine