{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T11:39:19Z","timestamp":1791027559456,"version":"4.1.0"},"reference-count":43,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5423","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[1999,6,25]]},"abstract":"<jats:p>Motilin is a 22\u2013amino acid peptide hormone expressed throughout the gastrointestinal (GI) tract of humans and other species. It affects gastric motility by stimulating interdigestive antrum and duodenal contractions. A heterotrimeric guanosine triphosphate\u2013binding protein (G protein)\u2013coupled receptor for motilin was isolated from human stomach, and its amino acid sequence was found to be 52 percent identical to the human receptor for growth hormone secretagogues. The macrolide antibiotic erythromycin also interacted with the cloned motilin receptor, providing a molecular basis for its effects on the human GI tract. The motilin receptor is expressed in enteric neurons of the human duodenum and colon. Development of motilin receptor agonists and antagonists may be useful in the treatment of multiple disorders of GI motility.<\/jats:p>","DOI":"10.1126\/science.284.5423.2184","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T09:37:20Z","timestamp":1027762640000},"page":"2184-2188","source":"Crossref","is-referenced-by-count":338,"title":["Receptor for Motilin Identified in the Human Gastrointestinal System"],"prefix":"10.1126","volume":"284","author":[{"given":"Scott D.","family":"Feighner","sequence":"first","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carina P.","family":"Tan","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karen Kulju","family":"McKee","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oksana C.","family":"Palyha","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Donna L.","family":"Hreniuk","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sheng-Shung","family":"Pong","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher P.","family":"Austin","sequence":"additional","affiliation":[{"name":"Department of Human Genetics, Merck Research Laboratories, Sumneytown Pike, West Point, PA 19486, USA.4Department of Biochemistry and Molecular Biology, Merck-Frosst Center for Therapeutic Research, 16711 TransCanada Highway, Kirkland, Quebec H9H 3L1, Canada."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Figueroa","sequence":"additional","affiliation":[{"name":"Department of Human Genetics, Merck Research Laboratories, Sumneytown Pike, West Point, PA 19486, USA.4Department of Biochemistry and Molecular Biology, Merck-Frosst Center for Therapeutic Research, 16711 TransCanada Highway, Kirkland, Quebec H9H 3L1, Canada."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Douglas","family":"MacNeil","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Margaret A.","family":"Cascieri","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ravi","family":"Nargund","sequence":"additional","affiliation":[{"name":"Department of Medicinal Chemistry, Merck Research Laboratories, Building RY-80Y-265, 126 East Lincoln Avenue, Rahway, NJ 07065, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raman","family":"Bakshi","sequence":"additional","affiliation":[{"name":"Department of Medicinal Chemistry, Merck Research Laboratories, Building RY-80Y-265, 126 East Lincoln Avenue, Rahway, NJ 07065, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark","family":"Abramovitz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rino","family":"Stocco","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stacia","family":"Kargman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gary","family":"O'Neill","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lex H. T.","family":"Van Der","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"family":"Ploeg","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jilly","family":"Evans","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arthur A.","family":"Patchett","sequence":"additional","affiliation":[{"name":"Department of Medicinal Chemistry, Merck Research Laboratories, Building RY-80Y-265, 126 East Lincoln Avenue, Rahway, NJ 07065, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roy G.","family":"Smith","sequence":"additional","affiliation":[{"name":"Huffington Center on Aging and Department of Cell Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030\u20133498, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew D.","family":"Howard","sequence":"additional","affiliation":[{"name":"Department of Metabolic Disorders,"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","doi-asserted-by":"publisher","DOI":"10.1159\/000171626"},{"key":"e_1_3_1_3_2","doi-asserted-by":"publisher","DOI":"10.1139\/o73-066"},{"key":"e_1_3_1_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0196-9781(96)00333-6"},{"key":"e_1_3_1_5_2","unstructured":"P. Poitras in Gut Peptides: Biochemistry and Physiology J. H. Walsh and G. J. Dockray Eds. (Raven New York 1994) pp. 261\u2013304."},{"key":"e_1_3_1_6_2","doi-asserted-by":"publisher","DOI":"10.1006\/phrs.1996.0030"},{"key":"e_1_3_1_7_2","first-page":"G688","volume":"247","author":"Itoh Z.","year":"1984","unstructured":"Itoh Z., Nakaya M., Suzuki T., Am. J. Physiol. 247, G688 (1984).","journal-title":"Am. J. Physiol."},{"key":"e_1_3_1_8_2","first-page":"485","volume":"88","author":"Weber F. H.","year":"1993","unstructured":"Weber F. H., Richards R. D., McCallum R. W., Am. J. Gastroenterol. 88, 485 (1993).","journal-title":"Am. J. Gastroenterol."},{"key":"e_1_3_1_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/0014-5793(87)80512-4"},{"key":"e_1_3_1_10_2","doi-asserted-by":"publisher","DOI":"10.1210\/mend-2-2-175"},{"key":"e_1_3_1_11_2","doi-asserted-by":"publisher","DOI":"10.1089\/dna.1989.8.615"},{"key":"e_1_3_1_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/0014-5793(89)80633-7"},{"key":"e_1_3_1_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/0167-0115(94)90173-2"},{"key":"e_1_3_1_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-8993(97)01094-9"},{"key":"e_1_3_1_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/0196-9781(96)00053-8"},{"key":"e_1_3_1_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/0167-0115(88)90025-0"},{"key":"e_1_3_1_17_2","first-page":"227","volume":"55","author":"Depoortere I.","year":"1995","unstructured":"Depoortere I., Peeters T. L., ibid. 55, 227 (1995).","journal-title":"ibid."},{"key":"e_1_3_1_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/0196-9781(93)90169-H"},{"key":"e_1_3_1_19_2","first-page":"G994","volume":"272","author":"DePoortere I.","year":"1997","unstructured":"DePoortere I., Peeters T. L., Am. J. Physiol. 272, G994 (1997).","journal-title":"Am. J. Physiol."},{"key":"e_1_3_1_20_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.273.5277.974"},{"key":"e_1_3_1_21_2","doi-asserted-by":"publisher","DOI":"10.1006\/geno.1997.5069"},{"key":"e_1_3_1_22_2","doi-asserted-by":"publisher","DOI":"10.1210\/edrv.18.5.0316"},{"key":"e_1_3_1_23_2","unstructured":"Inspection of the GPR38 genomic DNA sequence revealed two potential mRNA splice sites corresponding to consensus boundaries for exon-intron junctions ["},{"key":"e_1_3_1_23_3","doi-asserted-by":"publisher","DOI":"10.1016\/0076-6879(90)83018-5"},{"key":"e_1_3_1_23_4","unstructured":"]. An imperfect donor site [TGC\/gt; perfect donor sequence (CCG\/gt)] was found at nucleotides 1929 to 1931 [of the 3068\u2013base pair (bp) genomic fragment of GPR38 including 5\u2032 untranslated region and intron]; a perfect splice-donor site was found at nucleotides 2080 to 2082; and a perfect splice-acceptor site [sequence (pyrimidine-rich stretch ag\/TG)] was found at nucleotide 2729. To determine which splice forms exist naturally we performed RACE on polyadenylated [poly(A) + ] mRNA isolated from human thyroid gland and we conducted RT-PCR on HEK-293\/aeq17 cells transfected with an expression plasmid containing the GPR38 genomic DNA intron. Directional RACE reactions were conducted on 1 \u03bcg of thyroid poly(A) + mRNA that contained RNA encoding GPR38 (20). Primers were synthesized corresponding to the 5\u2032 end of the coding region of GPR38 (AP1: 5\u2032-CCATCCTAATACGACTCACTATAGGGC) and the 3\u2032 end of the GPR38 coding region including the translation termination codon TAA (5\u2032 RACE1: 5\u2032-TTATCCCATCGTCTTCACGTTAGCGCTTGTCTC). Conditions (Marathon cDNA Touchdown PCR; Clontech Palo Alto CA) were as follows: 94\u00b0C for 1 min; 5 cycles of 94\u00b0C for 30 s and 72\u00b0C for 4 min; 5 cycles of 94\u00b0C for 30 s and 70\u00b0C for 4 min; and 25 cycles of 94\u00b0C for 20 s and 68\u00b0C for 4 min. An \u223c1.4-kb amplified product was identified that hybridized with a 32 P-labeled probe derived from the TM2 to TM4 region (3F\/4R probe) of GPR38. This product was subcloned into PCR-Script vector (Invitrogen) and sequenced. We confirmed these results using RT-PCR by transfecting an expression plasmid containing the GPR38 gene (the complete open reading frame interrupted by a single intron of \u223c0.7 kb) into HEK-293\/aeq17 cells. RNA was then isolated [poly(A) + Pure Kit Ambion] and subjected to Northern (RNA) blot analysis with the 3F\/4R probe which revealed two hybridizing bands: a 2.4-kb band containing the unspliced intron and a \u223c1.4-kb band containing spliced forms. RT-PCR was then performed (Superscript 2 One-Step Kit Life Technologies) on mRNA from transfected HEK-293\/aeq17 cells with the forward primer 5\u2032 RACE1 and reverse primer 3\u2032 RACE2 (TM5 region: 5\u2032-CTGCCCTTTCTGTGCCTCAGCATCCTCTAC). An \u223c500-bp product was cloned (TA vector pCR2.2 Invitrogen Carlsbad CA) sequenced and found to be a mixture of both spliced forms. Assembly of the complete open reading frame for GPR38-A without intronic sequence was performed by ligation of an exon 1 fragment (Not I digestion of a MTL-R1A plasmid containing the intron in pCDNA-3) to pCDNA-3.1 containing a Not I\u2013EcoR I exon 2 fragment."},{"key":"e_1_3_1_24_2","doi-asserted-by":"publisher","DOI":"10.1089\/dna.1992.11.1"},{"key":"e_1_3_1_25_2","doi-asserted-by":"publisher","DOI":"10.1038\/366265a0"},{"key":"e_1_3_1_26_2","unstructured":"GenBank database [D. Benson M. S. Boguski D. J. Lipman J. Ostell B. F. Ouellette Nucleic Acids Res. 26 1 (1998)] assession numbers are as follows: human GHS-R (HSU60179) human GPR38-A (MTL-R1A) (O43193) and fish clone 75E7 (AF082210). The alignment data are available at www.sciencemag.org\/feature\/data\/1039909.shl"},{"key":"e_1_3_1_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/0143-4160(93)90091-J"},{"key":"e_1_3_1_28_2","doi-asserted-by":"publisher","DOI":"10.1210\/mend.11.4.9908"},{"key":"e_1_3_1_29_2","unstructured":"Measurement of GPR38-A activity in the aequorin-expressing stable reporter cell line HEK-293\/aeq17 was made with a Luminoskan RT luminometer (Labsystems Gaithersburg MD). HEK-293\/aeq17cells (8 \u00d7 10 5 cells plated 18 hours before transfection) were transfected with 11 \u03bcg of human GPR38-A plasmid DNA in the presence of 132 \u03bcg of lipofectamine (Life Technologies Gaithersburg MD). After 40 hours the apo-aequorin in the cells was converted to holo-aequorin by incubation for an additional 1 hour in the presence of the essential chromophore coelenterazine (10 \u03bcM; Molecular Probes Eugene OR) under reducing conditions (300 \u03bcM reduced glutathione) in ECB buffer [140 mM NaCl 20 mM KCl 20 mM Hepes-NaOH pH 7.4 5 mM glucose 1 mM MgCl 2 1 mM CaCl 2 and bovine serum albumin (BSA; 0.1 mg\/ml)] transferred into ECB buffer washed once and resuspended to 500 000 cells\/ml. A 100-\u03bcl sample of cell suspension (corresponding to 5 \u00d7 10 4 cells) was then injected into the test ligand plate (96-well format) and the integrated light emission was recorded over 30 s in 0.5-s units. Lysis buffer (20 \u03bcl) (0.1% final Triton X-100 concentration) was then injected and the integrated light emission recorded over 10 s in 0.5-s units. The fractional response values for each well were calculated by taking the ratio of the integrated response to the initial challenge to the total integrated luminescence including the Triton X-100 lysis response."},{"key":"e_1_3_1_30_2","unstructured":"To place an NH 2 -terminal FLAG epitope in frame with the GPR38-A coding sequence we constructed a mammalian expression vector by ligating a Pme I fragment excised from the pcDNA-1.1 expression vector (Invitrogen Carlsbad CA) containing GPR38 into the Eco RV site of pFLAG\/CMV-2 vector (Kodak Imaging Systems New Haven CT). After lipofection (Life Technologies Gaithersberg MD) of this plasmid into HEK-293\/aeq17 cells a protein of the expected size (\u223c45 kD) was detected in crude cell membranes by protein immunoblot analysis with the M1 monoclonal antibody to FLAG (Kodak Imaging Systems)."},{"key":"e_1_3_1_31_2","unstructured":"Ligand plates were assembled from commercial sources (Research Biochemicals International Natick MA; Phoenix Pharmaceuticals Mountain View CA) and contained an assortment of nonpeptide small molecules: for example adenosines\/purinerigics (theophylline reserpine phenyltoin phenylbutazone) adrenergics\/histaminergics (alprenolol prazocin phentolamine histamine cimetidine) cholinergics\/ion channel modulators (carbachol atropine amiloride diltiazem Bay K-8644) dopaminergics (ergocristine haloperidol clozapine bromocryptine) glutamatergics (aspartic acid capsaicin glutamic acid kainic acid quisqualic acid) opioids (levallorphan natrexone norcodeine nalaxone) serotonergics (ketanserin quipazine mianserin tryptophan) enzyme inhibitors\/GABAergics (captopril papaverine baclofen allopurinol indomethicin erythromycin) and peptides (deltorphin thrombin cortistatin amylin neuromedin B guanylin neuropeptide EI enterostatin dynorphin A amyloid b-protein secretin \u03b2-MSH endothelin-3 GLP-1 GLP-2 TRH adrenomedullin BNP-32 ANF katacalcin galanin pancreastatin PACAP \u03b3-MSH urotensin calcitonin PTH CRF prodynorphin vasopressin motilin valosin NPY 13-16 NPY 3-36 IL-8 thymosin C5a RANTES GnRH oxytocin substance P VIP somatostatin bombesin b-endorphin GHRP-6 endothelin-1 ACTH angiotensin-2 bradykinin fMLP neurotensin glucagon CGRP [des-Arg-9]bradykinin endothelin-2 and gastrin)."},{"key":"e_1_3_1_32_2","first-page":"G469","volume":"257","author":"Peeters T.","year":"1989","unstructured":"Peeters T., et al., Am. J. Physiol. 257, G469 (1989).","journal-title":"Am. J. Physiol."},{"key":"e_1_3_1_33_2","unstructured":"Human motilin (COOH-terminally amidated; Research Genetics Huntsville AL) was radiolabeled with 125 I at Tyr 7 to a specific activity of \u223c2000 Ci\/mmol (Woods Assay Portland OR). The binding of human 125 I-motilin to crude cell membranes prepared from HEK-293\/aeq17 cells expressing MTL-R1A was determined as follows. Membranes were prepared on ice 48 hours after transfection. Cells were washed twice with 10 ml of phosphate-buffed saline and once with 1 ml of homogenization buffer (HB: 50 mM tris-HCl pH 7.4 10 mM MgCl 2 ). Cells were scraped into 10 ml of HB and then lysed with a Polytron device (Brinkmann Syosset NY; three bursts of 10 s at setting 4). The homogenate was centrifuged for 20 min at 11 000 g at 0\u00b0C then the crude membrane pellet was resuspended in HB supplemented with 1.5% BSA and kept on ice. Binding reactions were performed at 20\u00b0C for 1 hour in 0.5 ml containing 0.1 ml of membrane suspension (\u223c1 \u03bcg of protein) 10 \u03bcl of human 125 I-motilin 10 \u03bcl of competing peptide and 380 to 390 \u03bcl of HB. Bound radioligand was separated by rapid vacuum filtration through GF\/C grade filters (Whatman Maidstone UK) that were pretreated for 1 hour with 0.5% polyethylenimine. After application of the membrane suspension to the filter the filter was washed three times with 3 ml of ice-cold HB buffer. Radioactivity bound to the filters was quantitated by gamma counting. Specific binding was defined as the difference between total binding and nonspecific binding that occurred in the presence of 100 nM unlabeled human motilin."},{"key":"e_1_3_1_34_2","first-page":"413","volume":"48","author":"Kenakin T.","year":"1996","unstructured":"Kenakin T., Pharmacol. Rev. 48, 413 (1996).","journal-title":"Pharmacol. Rev."},{"key":"e_1_3_1_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/0196-9781(92)90090-P"},{"key":"e_1_3_1_36_2","first-page":"11","volume":"16","author":"Miller P.","year":"1995","unstructured":"Miller P., et al., ibid. 16, 11 (1995).","journal-title":"ibid."},{"key":"e_1_3_1_37_2","unstructured":"In situ hybridization was performed on 8-\u03bcm-thick formalin-fixed paraffin-embedded sections with a digoxigenin-labeled complementary RNA probe corresponding to the complete open reading frame of MTL-R1A with tyramide\u2013Texas Red detection as described ["},{"key":"e_1_3_1_37_3","doi-asserted-by":"publisher","DOI":"10.1038\/915"},{"key":"e_1_3_1_37_4","unstructured":"]. NOS was detected with an antibody and visualized with a fluorescein isothiocyanate (FITC)\u2013conjugated secondary antibody (Santa Cruz Biotechnology Santa Cruz CA). Sections were counterstained for nuclear detection with 4\u2032 6-diamidoino-2 phenylindole (DAPI). Human tissues were obtained from the National Disease Research Interchange (Philadelphia PA)."},{"key":"e_1_3_1_38_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0016-5085(97)70011-8"},{"key":"e_1_3_1_39_2","unstructured":"RNA encoding MTL-R1A was detected by RNase Protection Assay (RPA) (MAXIscript and HybSpeed RPA kits; Ambion Austin TX). The anti-sense MTL-R1A probe corresponded to nucleotides 1234 to 1516 of the human MTL-1A with \u223c60 nucleotides of vector sequence (pLitmus 28 New England Biolabs Beverly MA). Poly(A)+ mRNA from tissues was purchased from Clontech (Palo Alto CA)."},{"key":"e_1_3_1_40_2","unstructured":"Single-letter abbreviations for the amino acid residues are as follows: A Ala; C Cys; D Asp; E Glu; F Phe; G Gly; H His; I Ile; K Lys; L Leu; M Met; N Asn; P Pro; Q Gln; R Arg; S Ser; T Thr; V Val; W Trp; Y Tyr; and L n n Leu."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.284.5423.2184","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,13]],"date-time":"2024-01-13T09:38:56Z","timestamp":1705138736000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.284.5423.2184"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,6,25]]},"references-count":43,"journal-issue":{"issue":"5423","published-print":{"date-parts":[[1999,6,25]]}},"alternative-id":["10.1126\/science.284.5423.2184"],"URL":"https:\/\/doi.org\/10.1126\/science.284.5423.2184","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,6,25]]}}}