title: Molecular and functional characterization of monocot-specific Pex5p splicing variants, using OsPex5pL and OsPex5pS from rice (Oryza sativa).
abstract: We identified two alternatively spliced variants of the peroxisomal targeting signal 1 (PTS1) receptor protein Pex5ps in monocot (rice, wheat, and barley) but not in dicot (Arabidopsis and tobacco) plants. We characterized the molecular and functional differences between the rice (Oryza sativa) Pex5 splicing variants OsPex5pL and OsPex5pS. There is only a single-copy of OsPEX5 in the rice genome and RT-PCR analysis points to alternative splicing of the transcripts. Putative light-responsive cis-elements were identified in the 5' region flanking OsPEX5L and Northern blot analysis demonstrated that this region affected light-dependent expression of OsPEX5 transcription. Using the pex5-deficient yeast mutant Scpex5, we showed that OsPex5pL and OsPex5pS are able to restore translocation of a model PTS1 protein (GFP-SKL) into peroxisomes. OsPex5pL and OsPex5pS formed homo-complexes via specific interaction domains, and interacted with each other and OsPex14p to form hetero-complexes. Although overexpression of OsPex5pL in the Arabidopsis pex5 mutant (Atpex5) rescued the mutant phenotype, overexpression of OsPex5pS only resulted in partial recovery.
authors.affiliation: Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Jung Ro
authors.initials: JR
authors.lastname: Lee
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Jung
authors.forename: Jae Sook
authors.initials: JS
authors.lastname: Kang
authors.forename: Jong Cheol
authors.initials: JC
authors.lastname: Kim
authors.forename: In Jung
authors.initials: IJ
authors.lastname: Jung
authors.forename: Min Sook
authors.initials: MS
authors.lastname: Seok
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Kim
authors.forename: Woe Yeon
authors.initials: WY
authors.lastname: Kim
authors.forename: Min Gab
authors.initials: MG
authors.lastname: Kim
authors.forename: Jae-Yean
authors.initials: JY
authors.lastname: Kim
authors.forename: Chae Oh
authors.initials: CO
authors.lastname: Lim
authors.forename: Kyun Oh
authors.initials: KO
authors.lastname: Lee
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D017398:Alternative Splicing; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D000074435:Peroxisome-Targeting Signal 1 Receptor; D020675:Peroxisomes / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; C499509:PEX5 protein, S cerevisiae; D000074435:Peroxisome-Targeting Signal 1 Receptor; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins