title: REEP1 and REEP2 proteins are preferentially expressed in neuronal and neuronal-like exocytotic tissues.
abstract: The six members of the Receptor Expression Enhancing Protein (REEP) family were originally identified based on their ability to enhance heterologous expression of olfactory receptors and other difficult to express G protein-coupled receptors. Interestingly, REEP1 mutations have been linked to neurodegenerative disorders of upper and lower motor neurons, hereditary spastic paraplegia (HSP) and distal hereditary motor neuropathy type V (dHMN-V). The closely related REEP2 isoform has not demonstrated any such disease linkage. Previous research has suggested that REEP1 mRNA is ubiquitously expressed in brain, muscle, endocrine, and multiple other organs, inconsistent with the neurodegenerative phenotype observed in HSP and dHMN-V. To more fully examine REEP1 expression, we developed and characterized a new REEP1 monoclonal antibody for both immunoblotting and immunofluorescent microscopic analysis. Unlike previous RT-PCR studies, immunoblotting demonstrated that REEP1 protein was not ubiquitous; its expression was restricted to neuronal tissues (brain, spinal cord) and testes. Gene expression microarray analysis demonstrated REEP1 and REEP2 mRNA expression in superior cervical and stellate sympathetic ganglia tissue. Furthermore, expression of endogenous REEP1 was confirmed in cultured murine sympathetic ganglion neurons by RT-PCR and immunofluorescent staining, with expression occurring between Day 4 and Day 8 of culture. Lastly, we demonstrated that REEP2 protein expression was also restricted to neuronal tissues (brain and spinal cord) and tissues that exhibit neuronal-like exocytosis (testes, pituitary, and adrenal gland). In addition to sensory tissues, expression of the REEP1/REEP2 subfamily appears to be restricted to neuronal and neuronal-like exocytotic tissues, consistent with neuronally restricted symptoms of REEP1 genetic disorders.
authors.affiliation: Department of Anesthesia/CCM, Stanford University Medical School, Stanford, CA 94305.
authors.forename: Carl M
authors.initials: CM
authors.lastname: Hurt
authors.affiliation: Department of Anesthesia/CCM, Stanford University Medical School, Stanford, CA 94305.|Department of Pharmacology, Drug Development and Therapeutics, Institute of Biomedicine, University of Turku, Turku, Finland FI-20520.
authors.forename: Susann
authors.initials: S
authors.lastname: Björk
authors.affiliation: Department of Anesthesia/CCM, Stanford University Medical School, Stanford, CA 94305.
authors.forename: Vincent K
authors.initials: VK
authors.lastname: Ho
authors.affiliation: Institute of Experimental and Clinical Pharmacology and Toxicology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany 79104.
authors.forename: Ralf
authors.initials: R
authors.lastname: Gilsbach
authors.affiliation: Institute of Experimental and Clinical Pharmacology and Toxicology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany 79104.
authors.forename: Lutz
authors.initials: L
authors.lastname: Hein
authors.affiliation: Department of Anesthesia/CCM, Stanford University Medical School, Stanford, CA 94305.
authors.forename: Timothy
authors.initials: T
authors.lastname: Angelotti
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D001921:Brain / Q000378:metabolism*; D005728:Ganglia, Sympathetic / Q000378:metabolism*; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000276:immunology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D013116:Spinal Cord / Q000378:metabolism; D013737:Testis / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D026901:Membrane Transport Proteins; C495318:REEP1 protein, human
keywords: AR; Distal hereditary motor neuropathy type V; G protein-coupled receptor; GPCR; HSP; Hereditary spastic paraplegia; NGF; Neurodegeneration; OR; REEP; RT-PCR; RTP; Receptor expression enhancing protein; SCG; SG; Sympathetic ganglion neuron; Yip; Ypt interacting protein; adrenergic receptor; dHMN-V; distal hereditary motor neuropathy type V; hereditary spastic paraplegia; mAb; monoclonal antibody; nerve growth factor; olfactory receptor; receptor expression enhancing protein; receptor transporting protein; reverse transcription polymerase chain reaction; stellate ganglion, SGN, sympathetic ganglion neurons; superior cervical ganglia