7. 穀類種子に存在するアラビノガラクタン蛋白質 (AGP) の単離・同定 : ジベレリン作用との関連性の追求

概要

論文の詳細を見る
Arabinogalactan-proteins (AGPs) are proteoglycans rich in hydroxyproline. Glycosylphosphatidylinositol (GPI)-anchoring is another characteristics of AGPs, suggesting their possible involvement in signal transduction. We have shown that plasma membrane-AGPs are essential to GA signal transduction in barley aleurone layers. AGPs extracted from aleurone layers are separated into two major fractions by RP-HPLC (FrA of a smaller tR and FrB of a larger tR). FrB was specifically detected in aleurone layers. Characterization of AGPs present in aleurone layers in molecular level is important to understand their roles in GA signaling. We examined AGPs in rice brans because of their availability in larger scale than barley, and of another advantage of the accessibility to rice database. We purified AGPs in rice brans by using β-Yariv reagent that binds AGPs selectively. Rice brans showed two major AGPs fractions corresponding to FrA and FrB on RP-HPLC as barley did. Peptide sequencing of FrA showed two different N-terminal sequences. One of them corresponded to two different ORFs encoding a same mature AG-peptide backbone. The other was assigned to a classical AGP-like protein. AGPs in membrane fraction of rice brans were also studied. Membrane extract gave a β-Yariv-reactive fraction (FrC) of a larger tR than FrB on RP-HPLC. Treated with PI-PLC, the β-Yalive reactive peak in FrC shifted to a smaller tR identical to that of FrA. This result indicates that FrC contains GPI-anchored AGPs and at least part of AGPs in FrA are derived from those in FrC by cleavage of GPI-anchor. Identification of AGPs in FrB and functional analysis of aleurone AGPs have yet to be done to show their involvement in GA action.
植物化学調節学会の論文
2003-10-10

7. 穀類種子に存在するアラビノガラクタン蛋白質 (AGP) の単離・同定 : ジベレリン作用との関連性の追求

スポンサーリンク

概要

著者

関連論文

スポンサーリンク