title: Labeling substrates of protein arginine methyltransferase with engineered enzymes and matched S-adenosyl-L-methionine analogues.
abstract: Elucidating physiological and pathogenic functions of protein methyltransferases (PMTs) relies on knowing their substrate profiles. S-adenosyl-L-methionine (SAM) is the sole methyl-donor cofactor of PMTs. Recently, SAM analogues have emerged as novel small-molecule tools to efficiently label PMT substrates. Here we reported the development of a clickable SAM analogue cofactor, 4-propargyloxy-but-2-enyl SAM, and its implementation to label substrates of human protein arginine methyltransferase 1 (PRMT1). In the system, the SAM analogue cofactor, coupled with matched PRMT1 mutants rather than native PRMT1, was shown to label PRMT1 substrates. The transferable 4-propargyloxy-but-2-enyl moiety of the SAM analogue further allowed corresponding modified substrates to be characterized through a subsequent click chemical ligation with an azido-based probe. The SAM analogue, in combination with a rational protein-engineering approach, thus shows potential to label and identify PMT targets in the context of a complex cellular mixture.
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Weihong
authors.initials: W
authors.lastname: Zheng
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Yu
authors.forename: Haiteng
authors.initials: H
authors.lastname: Deng
authors.forename: Minkui
authors.initials: M
authors.lastname: Luo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D008969:Molecular Sequence Data; D015202:Protein Engineering; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D012436:S-Adenosylmethionine; D011484:Protein-Arginine N-Methyltransferases