title: A mitochondria-localized glutamic acid-rich protein (MGARP/OSAP) is highly expressed in retina that exhibits a large area of intrinsic disorder.
abstract: Study of retina specific genes would offer insights into retinal diseases and treatment. Based on the information from the gene expression profiles of mouse retinas, we here identified a mitochondria-localized glutamic acid-rich protein (MGARP/OSAP) as one of the highly expressed proteins in retina. Sequence analysis revealed that mouse and rat MGARPs have an extra insertion of four consecutive amino acid repeats at the C-terminus, while other homologues do not. MGARP was demonstrated to be localized to the mitochondria and overexpression of MGARP missing N-terminal region causes severe mitochondrial aggregation, implying an important role of MGARP in maintaining mitochondrial morphology. MGARP is highly expressed in mitochondria-rich layers, including inner segment of the photoreceptor, outer plexiform layer and ganglion cell layers of mouse retina. Far-UV CD spectrum analysis suggested that MGARP exhibits a large area of intrinsic disorder and the unusual position of its Tyr fluorescence suggested that Tyr residues in MGARP might form excimer and exist in an ionized state. These findings implied that MGARP be a good candidate for assembling certain ion channels on mitochondria membrane and have great potential to be involved in retinal energetic metabolism through mitochondria related pathway.
authors.affiliation: Department of Biological Sciences and Biotechnology, State-Key Lab of Biomembranes and Membrane Biotechnology, Tsinghua University, Haidian District, 100084 Beijing, China.
authors.forename: Shaoling
authors.initials: S
authors.lastname: Qi
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Mingxue
authors.initials: M
authors.lastname: Zhou
authors.forename: Yunxiao
authors.initials: Y
authors.lastname: Ge
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Samuel Shao-Min
authors.initials: SS
authors.lastname: Zhang
authors.forename: Shuping
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005136:Eye Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D012164:Retinal Diseases / Q000378:metabolism; D016415:Sequence Alignment; D014018:Tissue Distribution
chemical_list: D005136:Eye Proteins; C509731:MGARP protein, mouse; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011993:Recombinant Fusion Proteins