title: Two novel mammalian Nogo receptor homologs differentially expressed in the central and peripheral nervous systems.
abstract: The regenerative capacity of the adult mammalian central nervous system is restricted by the myelinating oligodendrocytes that form a nonpermissive environment for axonal growth. Currently only the Nogo receptor (NgR), in complex with p75(NTR) neurotrophin receptor is known to be involved in this inhibitory signalling in neurons. NgR is a common receptor for the three inhibitory myelin proteins Nogo-A, OMgp, and MAG. Here we describe two novel Nogo receptor gene homologs named NGRL2 and NGRL3 from human and mouse that, like NGR, encode putative leucine-rich repeat containing GPI-anchored proteins. We show by in situ hybridisation and by RT-PCR that NGRL mRNAs are predominantly expressed in the neurons of the embryonic and adult central and peripheral nervous systems, and that they together with NGR possess distinct and partially nonoverlapping expression patterns. We also show that all four members of the reticulon family, including Nogo-A, are widely expressed in the nervous system, and therefore are possible ligands for the NgRLs.
authors.affiliation: Program in Molecular Neurobiology, Institute of Biotechnology, University of Helsinki, P.O. Box 56 (Viikinkaari 9), FIN-00014, University of Helsinki, Helsinki, Finland. Juha.Lauren@Helsinki.Fi
authors.forename: Juha
authors.initials: J
authors.lastname: Laurén
authors.forename: Matti S
authors.initials: MS
authors.lastname: Airaksinen
authors.forename: Mart
authors.initials: M
authors.lastname: Saarma
authors.forename: Tõnis
authors.initials: T
authors.lastname: Timmusk
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002490:Central Nervous System / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D005333:Fetus; D058851:GPI-Linked Proteins; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics; D009185:Myelin Proteins / Q000378:metabolism*; D009416:Nerve Regeneration / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000235:genetics; D000070798:Nogo Proteins; D000070816:Nogo Receptor 1; D009836:Oligodendroglia / Q000378:metabolism; D017933:Peripheral Nervous System / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface; D018000:Receptors, Peptide / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018076:DNA, Complementary; D058851:GPI-Linked Proteins; D008024:Ligands; D008565:Membrane Proteins; D009124:Muscle Proteins; D009185:Myelin Proteins; D009419:Nerve Tissue Proteins; D000070798:Nogo Proteins; D000070816:Nogo Receptor 1; D012333:RNA, Messenger; C000603199:RTN4 protein, human; D011956:Receptors, Cell Surface; D018000:Receptors, Peptide; C484735:Rtn2 protein, mouse; C000603201:Rtn4 protein, mouse; C000603197:Rtn4 protein, rat; C486581:Rtn4r protein, rat