Pathogenesis-related protein 10 isolated from hot pepper functions as a ribonuclease in an antiviral pathway.
A hot pepper (Capsicum annuum) cDNA clone encoding pathogenesis-related protein 10 (CaPR-10) was isolated by differential screening of a cDNA library prepared from pepper leaves inoculated with tobacco mosaic virus pathotype (TMV-P0). CaPR-10 transcripts were induced in the incompatible interaction with TMV-P0 or Xanthomonas campestris pv. vesicatoria (Xcv) but not induced in the compatible interaction. Characterization of enzymatic properties of CaPR-10 indicated that the recombinant protein exhibits a ribonucleolytic activity against TMV RNA, as well as against pepper total RNA, and shows its putative antiviral activity in several conditions. The CaPR-10 protein existed at very low level in leaf tissue but was dramatically induced as soon as plants were inoculated with TMV-P0, and this was correlated with the increase of its ribonucleolytic activity. Immunoblot analysis and pull-down assays using proteins extracted from pepper leaves showed that TMV-P0 inoculation led to the phosphorylation of CaPR-10, a modification that should affect its capacity for RNase function. We present data that the induction and subsequent phosphorylation of CaPR-10 increased its ribonucleolytic activity to cleave invading viral RNAs, and this activity should be important to its antiviral pathway during viral attack in vivo.
Park
Chang-Jin
CJ
School of Lifesciences and Biotechnology, Korea University 1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-701, Korea.
Kim
Ki-Jeong
KJ
Shin
Ryoung
R
Park
Jeong Mee
JM
Shin
Yun-Chul
YC
Paek
Kyung-Hee
KH
D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002212:Capsicum / Q000201:enzymology*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D012260:Ribonucleases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D000890:Anti-Infective Agents; D017931:DNA Primers; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D012260:Ribonucleases; D006026:Glycoside Hydrolases