title: A proteomics strategy for the identification of FAT10-modified sites by mass spectrometry.
abstract: The ubiquitin-like protein FAT10 (HLA-F adjacent transcript 10) is uniquely expressed in mammals. The fat10 gene is encoded in the MHC class I locus in the human genome and is related to some specific processes, such as apoptosis, immune response, and cancer. However, biological knowledge of FAT10 is limited, owing to the lack of identification of its conjugates. FAT10 covalently modifies proteins in eukaryotes, but only a few substrates of FAT10 have been reported until now, and no FATylated sites have been identified. Here, we report the proteome-scale identification of FATylated proteins by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We identified 175 proteins with high confidence as FATylated candidates. A total of 13 modified sites were identified for the first time by a modified search of the raw MS data. The modified sites were highly enriched with hydrophilic amino acids. Furthermore, the FATylation processes of hnRNP C2, PCNA, and PDIA3 were verified by a coimmunoprecipitation assay. We confirmed that most of the substrates were covalently attached to a FAT10 monomer. The functional distribution of the FAT10 targets suggests that FAT10 participates in various biological processes, such as translation, protein folding, RNA processing, and macromolecular complex assembly. These results should be very useful for investigating the biological functions of FAT10.
authors.affiliation: State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences Beijing, Beijing Institute of Radiation Medicine , Beijing 102206, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Leng
authors.forename: Changming
authors.initials: C
authors.lastname: Xu
authors.forename: Chao
authors.initials: C
authors.lastname: Wei
authors.forename: Jiyang
authors.initials: J
authors.lastname: Zhang
authors.forename: Boya
authors.initials: B
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Weijie
authors.initials: W
authors.lastname: Qin
authors.forename: Wanjun
authors.initials: W
authors.lastname: Zhang
authors.forename: Chengpu
authors.initials: C
authors.lastname: Zhang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Xing
authors.forename: Linhui
authors.initials: L
authors.lastname: Zhai
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Mansheng
authors.initials: M
authors.lastname: Li
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Jin
authors.forename: Yanzhi
authors.initials: Y
authors.lastname: Yuan
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
authors.forename: Jun
authors.initials: J
authors.lastname: Qin
authors.forename: Hongwei
authors.initials: H
authors.lastname: Xie
authors.forename: Fuchu
authors.initials: F
authors.lastname: He
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D040901:Proteomics; D014452:Ubiquitins / Q000737:chemistry / Q000235:genetics*
chemical_list: C109184:UBD protein, human; D014452:Ubiquitins