title: Identification of members of the Bex gene family as olfactory marker protein (OMP) binding partners.
abstract: Olfactory marker protein (OMP) expression is a hallmark of mature vertebrate olfactory receptor neurons (ORNs). Evidence for OMP function derives from altered behavioral and electrophysiological activities of OMP-KO mice. The molecular basis for the altered phenotype following the deletion of OMP is still unclear. Recent structural studies predict the involvement of OMP in protein-protein interaction. Here we report the identification of an OMP partner, Bex2, by phage-display screening of an olfactory mucosal cDNA-library. In situ hybridization demonstrates cellular co-localization of OMP mRNA with mRNAs for Bex1, Bex2, and Bex3 in ORNs of olfactory tissue of the mouse. The OMP/Bex interaction has been confirmed by demonstrating the chemical cross-linking of recombinant rat OMP with a synthetic peptide derived from the Bex amino acid sequence. The subcellular localization of Bex and OMP proteins was evaluated in transfected HEK293 cells. Bex is visualized in the nucleus and cytoplasm. Following co-transfection we observed the unexpected presence of some OMP in the nucleus along with Bex. Together, these data argue convincingly that we have identified Bex as an OMP partner whose further characterization will provide insight to the role of OMP and to the mechanism of the OMP/Bex interaction in ORN differentiation and function.
authors.affiliation: Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
authors.forename: Maik
authors.initials: M
authors.lastname: Behrens
authors.forename: Joyce W
authors.initials: JW
authors.lastname: Margolis
authors.forename: Frank L
authors.initials: FL
authors.lastname: Margolis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D051842:Olfactory Marker Protein; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000737:chemistry
chemical_list: D051017:Apoptosis Regulatory Proteins; C118512:Bex1 protein, mouse; C477719:Bex2 protein, rat; C485843:Bex3 protein, rat; D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; C485842:Ngfrap1 protein, mouse; D051842:Olfactory Marker Protein; C497598:Omp protein, mouse; D010446:Peptide Fragments; D011506:Proteins