Cloning of two splice variants of the rice PTS1 receptor, OsPex5pL and OsPex5pS, and their functional characterization using pex5-deficient yeast and Arabidopsis.
Using the rice PEX14 cDNA as a bait in a yeast two-hybrid assay, two splice variants of the type I peroxisomal targeting signal (PTS1) receptor, OsPex5pL and OsPex5pS, were cloned from a pathogen-treated rice leaf cDNA library. The proteins were produced from a single gene by alternative splicing, which generated a full-length variant, OsPEX5L, and a variant that lacked exon 7, OsPEX5S. OsPex5pL contained 11 copies of the pentapeptide motif WXXXF/Y in its N-terminus, and seven tetratricopeptide repeats in its C-terminus. Expression of OsPEX5L and OsPEX5S predominantly occurred in leaf tissues, and was induced by various stresses, such as exposure to the pathogen Magnaporthe grisea, and treatment with fungal elicitor, methyl viologen, NaCl or hydrogen peroxide. The Arabidopsis T-DNA insertional pex5 mutant, Atpex5, which does not germinate in the absence of sucrose and was resistant to indole-3-butyric acid (IBA), was perfectly rescued by over-expression of OsPex5pL, but not by OsPex5pS. Using transient expression of OsPex5pL and OsPex5pS in the Atpex5 mutant, we show that OsPex5pL translocates both PTS1- and PTS2-containing proteins into the peroxisome by interacting with OsPex7p, whereas OsPex5pS is involved only in PTS1-dependent import in Arabidopsis.
Lee
Jung Ro
JR
Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.
Jang
Ho Hee
HH
Park
Jin Ho
JH
Jung
Ji Hyun
JH
Lee
Seung Sik
SS
Park
Soo Kwon
SK
Chi
Yong Hun
YH
Moon
Jeong Chan
JC
Lee
Young Mee
YM
Kim
Sun Young
SY
Kim
Jae-Yean
JY
Yun
Dae-Jin
DJ
Cho
Moo Je
MJ
Lee
Kyun Oh
KO
Lee
Sang Yeol
SY
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D015723:Gene Library; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D000074435:Peroxisome-Targeting Signal 1 Receptor; D020675:Peroxisomes / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics
D000074435:Peroxisome-Targeting Signal 1 Receptor; D010940:Plant Proteins; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear