title: Drosophila retinophilin contains MORN repeats and is conserved in humans.
abstract: The function of conserved novel human genes can be efficiently addressed in genetic model organisms. From a collection of genes expressed in the Drosophila visual system, cDNAs expressed in vertebrates were identified and one similar to a novel human gene was chosen for further investigation. The results reported here characterize the Drosophila retinophilin gene and demonstrate that a similar gene is expressed in the human retina. The Drosophila and human retinophilin sequences are 50% identical, and they share an additional 16% conserved substitutions. Examination of the cDNA and genomic sequence indicates that it corresponds to the gene CG10233 of the annotated genome and predicts a 22.7 kDa protein. Polyclonal antibodies generated to a predicted retinophilin peptide recognize an antigen in Drosophila photoreceptor cells. The retinophilins encode 4 copies of a repeat associated with a Membrane Occupation and Recognition Nexus (MORN) function first discovered in junctophilins, which may interact with the plasma membrane. These results therefore show that Drosophila retinophilin is expressed in fly photoreceptor cells, demonstrate that a conserved human gene is expressed in human retina, and suggest that a mutational analysis of the Drosophila gene would be valuable.
authors.affiliation: Indiana University South Bend, South Bend, IN 46634, USA. kmecklen@iusb.edu
authors.forename: Kirk L
authors.initials: KL
authors.lastname: Mecklenburg
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D017434:Protein Structure, Tertiary
chemical_list: D029721:Drosophila Proteins; D005136:Eye Proteins; C520357:rtp protein, Drosophila