Nitration is exclusive to defense-related PR-1, PR-3 and PR-5 proteins in tobacco leaves.
Protein tyrosine nitration is an important post-translational modification. A variety of nitrated proteins are reported in Arabidopsis leaves and seedlings, sunflower hypocotyls, and pea roots. The identities of nitrated proteins are species-/organ-specific, and chloroplast proteins are most nitratable in leaves. However, precise mechanism is unclear. Here, we investigated nitroproteome in tobacco leaves following exposure to nitrogen dioxide. Proteins were extracted, electrophoresed and immunoblotted using an anti-3-nitrotyrosine antibody. Mass spectrometry and FASTA search identified for the first time an exclusive nitration of pathogenesis-related proteins, PR-1, PR-3 and PR-5, which are reportedly located in the apoplast or the vacuole. Furthermore, Tyr(36) of thaumatin-like protein E2 was identfied as a nitration site. The underlying mechanism and physiological relevance are discussed.
a Department of Mathematical and Life Sciences , Hiroshima University , Higashi-Hiroshima , Japan.
Misa
M
Takahashi
a Department of Mathematical and Life Sciences , Hiroshima University , Higashi-Hiroshima , Japan.
Jun
J
Shigeto
a Department of Mathematical and Life Sciences , Hiroshima University , Higashi-Hiroshima , Japan.
Shunsuke
S
Izumi
b Department of Biological Science , Hiroshima University, Higashi-Hiroshima , Hiroshima , Japan.
Katsutoshi
K
Yoshizato
a Department of Mathematical and Life Sciences , Hiroshima University , Higashi-Hiroshima , Japan.
Hiromichi
H
Morikawa
D009566:Nitrates / Q000378:metabolism*; D009585:Nitrogen Dioxide / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism
D009566:Nitrates; D010940:Plant Proteins; D009585:Nitrogen Dioxide
Apoplast; PR-1; PR-3; PR-5; defense/immunity-related proteins; nitrogen dioxide; pathogenesis-related proteins; protein tyrosine nitration; tobacco; vacuole