title: Using oriented peptide array libraries to evaluate methylarginine-specific antibodies and arginine methyltransferase substrate motifs.
abstract: Signal transduction in response to stimuli relies on the generation of cascades of posttranslational modifications that promote protein-protein interactions and facilitate the assembly of distinct signaling complexes. Arginine methylation is one such modification, which is catalyzed by a family of nine protein arginine methyltransferases, or PRMTs. Elucidating the substrate specificity of each PRMT will promote a better understanding of which signaling networks these enzymes contribute to. Although many PRMT substrates have been identified, and their methylation sites mapped, the optimal target motif for each of the nine PRMTs has not been systematically addressed. Here we describe the use of Oriented Peptide Array Libraries (OPALs) to methodically dissect the preferred methylation motifs for three of these enzymes - PRMT1, CARM1 and PRMT9. In parallel, we show that an OPAL platform with a fixed methylarginine residue can be used to validate the methyl-specific and sequence-specific properties of antibodies that have been generated against different PRMT substrates, and can also be used to confirm the pan nature of some methylarginine-specific antibodies.
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.|Graduate Program in EMC, UT GSBS, Houston, Texas 77030, USA.
authors.forename: Sitaram
authors.initials: S
authors.lastname: Gayatri
authors.affiliation: Epicypher Inc., Research Triangle Park, NC 27709, USA.
authors.forename: Martis W
authors.initials: MW
authors.lastname: Cowles
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.|Graduate Program in EMC, UT GSBS, Houston, Texas 77030, USA.
authors.forename: Vidyasiri
authors.initials: V
authors.lastname: Vemulapalli
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.
authors.forename: Donghang
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Epicypher Inc., Research Triangle Park, NC 27709, USA.
authors.forename: Zu-Wen
authors.initials: ZW
authors.lastname: Sun
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Bedford
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D000906:Antibodies / Q000737:chemistry*; D001120:Arginine / Q000737:chemistry*; D002460:Cell Line; D018604:Epitope Mapping; D044783:F-Box Proteins / Q000737:chemistry; D006801:Humans; D008745:Methylation; D051379:Mice; D019151:Peptide Library; D011499:Protein Processing, Post-Translational; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D012097:Repressor Proteins / Q000737:chemistry; D015398:Signal Transduction; D013379:Substrate Specificity
chemical_list: D000906:Antibodies; D044783:F-Box Proteins; D019151:Peptide Library; D011994:Recombinant Proteins; D012097:Repressor Proteins; D001120:Arginine; C457579:FBXO11 protein, human; C099988:PRMT1 protein, human; C546338:Prmt1 protein, mouse; D011484:Protein-Arginine N-Methyltransferases; C119966:coactivator-associated arginine methyltransferase 1