title: Identification and characterization of Xenopus OMP25.
abstract: This study describes the isolation of mitochondrial outer membrane protein 25 (OMP25) from Xenopus laevis and an analysis of its role in early development. X. laevis OMP25 (xOMP25) is a transmembrane protein of the mitochondrial outer membrane with a PDZ domain in the cytoplasmic tail, and an approximate molecular size of 25 kDa. We isolated xOMP25 from a cDNA library of X. laevis tailbud embryos. Amino acid sequence analysis of xOMP25 showed 57% identity to mouse OMP25, with 73% identity in the PDZ domains. XOMP25 mRNA is expressed maternally, and at a constant level throughout early development. The transcript is localized to eye, otic vesicle, branchial arch and neural tube. Mitochondrial targeting of an EGFP-fusion protein of xOMP25 was visualized using a mitochondria-specific fluorescent dye. Overexpression of xOMP25 in embryos caused curved axes, small eyes and disorganized head structures. Knockdown of xOMP25 protein using antisense morpholino oligonucleotides resulted in slightly shortened axes and decreased neural tissue. Although the mechanism remains unclear, our results implicate xOMP25 protein in the formation of the intact neural tube.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Inui
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D018076:DNA, Complementary; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014982:Xenopus laevis / Q000196:embryology
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger