title: Glucagon like-peptide-1 receptor is covalently modified by endogenous mono-ADP-ribosyltransferase.
abstract: Our previous study revealed a mono-ADP-ribosyltransferase mediated in vitro mono-ADP-ribosylation of IC(3) peptide, a peptide with sequence corresponded to third intracellular loop of glucagon like-peptide-1 (GLP-1) receptor. Furthermore, Arg(348) was shown to be modified amino acid residue although its mutation did not eliminate mono-ADP-ribosylation completely. In order to further study the signaling mechanisms of GLP-1 receptor, we took on lease a possibility that an alternative site of enzymatic modification exist so mono-ADP-ribosylation of Cys(341) was hypothesized. The results confirmed both Arg(348) and Cys(341) as a site of mono-ADP-ribosylation where Arg(348) is modified predominantly. Sum of mono-ADP-ribosylation rate of both single IC(3) mutants coincided with IC(3) rate. What is in vivo role of Cys(341) mono-ADP-ribosylation is entirely speculative but our study represents an important step toward a complete understanding of signaling via GLP-1 receptor.
authors: Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
authors: Matjaž
authors: M
authors: Deželak
authors: Aljoša
authors: A
authors: Bavec
mesh_terms: D036002:ADP Ribose Transferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D006224:Cricetinae; D003412:Cricetulus; D044387:GTP-Binding Protein beta Subunits / Q000378:metabolism; D000067757:Glucagon-Like Peptide-1 Receptor; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D018027:Receptors, Glucagon / Q000737:chemistry / Q000378:metabolism*
chemical_list: D044387:GTP-Binding Protein beta Subunits; D000067757:Glucagon-Like Peptide-1 Receptor; D010455:Peptides; D018027:Receptors, Glucagon; D036002:ADP Ribose Transferases