title: The 5-amino acid N-terminal extension of non-sulfated drosulfakinin II is a unique target to generate novel agonists.
abstract: The ability to design agonists that target peptide signaling is a strategy to delineate underlying mechanisms and influence biology. A sequence that uniquely characterizes a peptide provides a distinct site to generate novel agonists. Drosophila melanogaster sulfakinin encodes non-sulfated drosulfakinin I (nsDSK I; FDDYGHMRF-NH2) and nsDSK II (GGDDQFDDYGHMRF-NH2). Drosulfakinin is typical of sulfakinin precursors, which are conserved throughout invertebrates. Non-sulfated DSK II is structurally related to DSK I, however, it contains a unique 5-residue N-terminal extension; drosulfakinins signal through G-protein coupled receptors, DSK-R1 and DSK-R2. Drosulfakinin II distinctly influences adult and larval gut motility and larval locomotion; yet, its structure-activity relationship was unreported. We hypothesized substitution of an N-terminal extension residue may alter nsDSK II activity. By targeting the extension we identified, not unexpectedly, analogs mimicking nsDSK II, yet, surprisingly, we also discovered novel agonists with increased (super) and opposite (protean) effects. We determined [A3] nsDSK II increased larval gut contractility rather than, like nsDSK II, decrease it. [N4] nsDSK II impacted larval locomotion, although nsDSK II was inactive. In adult gut, [A1] nsDSK II, [A2] nsDSKII, and [A3] nsDSK II mimicked nsDSK II, and [A4] nsDSK II and [A5] nsDSK II were more potent; [N3] nsDSK II and [N4] nsDSK II mimicked nsDSK II. This study reports nsDSK II signals through DSK-R2 to influence gut motility and locomotion, identifying a novel role for the N-terminal extension in sulfakinin biology and receptor activation; it also led to the discovery of nsDSK II structural analogs that act as super and protean agonists.
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: M
authors.initials: M
authors.lastname: Leander
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: J
authors.initials: J
authors.lastname: Heimonen
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: T
authors.initials: T
authors.lastname: Brocke
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rasmussen
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bass
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: G
authors.initials: G
authors.lastname: Palmer
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: J
authors.initials: J
authors.lastname: Egle
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: M
authors.initials: M
authors.lastname: Mispelon
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: K
authors.initials: K
authors.lastname: Berry
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA. Electronic address: nicholsr@umich.edu.
authors.forename: R
authors.initials: R
authors.lastname: Nichols
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D007814:Larva / Q000187:drug effects / Q000235:genetics; D008124:Locomotion / Q000187:drug effects / Q000235:genetics*; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics; D010455:Peptides / Q000819:agonists* / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D011949:Receptors, Cholecystokinin / Q000737:chemistry / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: C581785:CCKLR-17D1 protein, Drosophila; C449649:CCKLR-17D3 protein, Drosophila; D029721:Drosophila Proteins; D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D010455:Peptides; D011949:Receptors, Cholecystokinin; D043562:Receptors, G-Protein-Coupled; C056936:drosulfakinin 1; C056938:drosulfakinin II
keywords: Cholecystokinin; DSK; FMRF-NH(2); FaRP; Gut motility; Locomotion; Molecular docking; Sulfakinin