title: MOR is not enough: identification of novel mu-opioid receptor interacting proteins using traditional and modified membrane yeast two-hybrid screens.
abstract: The mu-opioid receptor (MOR) is the G-protein coupled receptor primarily responsible for mediating the analgesic and rewarding properties of opioid agonist drugs such as morphine, fentanyl, and heroin. We have utilized a combination of traditional and modified membrane yeast two-hybrid screening methods to identify a cohort of novel MOR interacting proteins (MORIPs). The interaction between the MOR and a subset of MORIPs was validated in pulldown, co-immunoprecipitation, and co-localization studies using HEK293 cells stably expressing the MOR as well as rodent brain. Additionally, a subset of MORIPs was found capable of interaction with the delta and kappa opioid receptors, suggesting that they may represent general opioid receptor interacting proteins (ORIPS). Expression of several MORIPs was altered in specific mouse brain regions after chronic treatment with morphine, suggesting that these proteins may play a role in response to opioid agonist drugs. Based on the known function of these newly identified MORIPs, the interactions forming the MOR signalplex are hypothesized to be important for MOR signaling and intracellular trafficking. Understanding the molecular complexity of MOR/MORIP interactions provides a conceptual framework for defining the cellular mechanisms of MOR signaling in brain and may be critical for determining the physiological basis of opioid tolerance and addiction.
authors.affiliation: Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania, United States of America.
authors.forename: Jessica
authors.initials: J
authors.lastname: Petko
authors.forename: Stephanie
authors.initials: S
authors.lastname: Justice-Bitner
authors.forename: Jay
authors.initials: J
authors.lastname: Jin
authors.forename: Victoria
authors.initials: V
authors.lastname: Wong
authors.forename: Saranya
authors.initials: S
authors.lastname: Kittanakom
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Ferraro
authors.forename: Igor
authors.initials: I
authors.lastname: Stagljar
authors.forename: Robert
authors.initials: R
authors.lastname: Levenson
mesh_terms: D000701:Analgesics, Opioid / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D009020:Morphine / Q000494:pharmacology; D009687:Nuclear Proteins / Q000378:metabolism; D017465:Receptors, Opioid, delta / Q000378:metabolism; D017473:Receptors, Opioid, kappa / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects; D015003:Yeasts / Q000378:metabolism*; D000098563:Seven in Absentia Proteins
chemical_list: D000701:Analgesics, Opioid; D009687:Nuclear Proteins; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D009020:Morphine; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins