Molecular and functional characterization of monocot-specific Pex5p splicing variants, using OsPex5pL and OsPex5pS from rice (Oryza sativa).
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.
Lee
Jung Ro
JR
Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.
Jung
Ji Hyun
JH
Kang
Jae Sook
JS
Kim
Jong Cheol
JC
Jung
In Jung
IJ
Seok
Min Sook
MS
Kim
Ji Hye
JH
Kim
Woe Yeon
WY
Kim
Min Gab
MG
Kim
Jae-Yean
JY
Lim
Chae Oh
CO
Lee
Kyun Oh
KO
Lee
Sang Yeol
SY
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
D026901:Membrane Transport Proteins; C499509:PEX5 protein, S cerevisiae; D000074435:Peroxisome-Targeting Signal 1 Receptor; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins