摘要
Approximately 1% of plant proteins are predicted to be post-translationally modified with a glycosylphospha- tidylinositol （GPI） anchor that tethers the polypeptide to the outer leaflet of the plasma membrane. Whereas the synthesis and structure of GPI anchors is largely conserved across eukaryotes, the repertoire of functional domains present in the GPl-anchored proteome has diverged substantially. In plants, this includes a large fraction of the GPl-anchored proteome being further modified with plant-specific arabinogalactan （AG） O-glycans. The impor- tance of the GPl-anchored proteome to plant development is underscored by the fact that GPI biosynthetic null mutants exhibit embryo lethality. Mutations in genes encoding specific GPl-anchored proteins （GAPs） further supports their contribution to diverse biological processes, occurring at the interface of the plasma membrane and cell wall, including signaling, cell wall metabolism, cell wall polymer cross-linking, and plasmodesmatal transport. Here, we review the literature concerning plant GPl-anchored proteins, in the context of their potential to act as molecular hubs that mediate interactions between the plasma membrane and the cell wall, and their potential to transduce the signal into the protoplast and, thereby, activate signal transduction pathways.
Approximately 1% of plant proteins are predicted to be post-translationally modified with a glycosylphospha- tidylinositol （GPI） anchor that tethers the polypeptide to the outer leaflet of the plasma membrane. Whereas the synthesis and structure of GPI anchors is largely conserved across eukaryotes, the repertoire of functional domains present in the GPl-anchored proteome has diverged substantially. In plants, this includes a large fraction of the GPl-anchored proteome being further modified with plant-specific arabinogalactan （AG） O-glycans. The impor- tance of the GPl-anchored proteome to plant development is underscored by the fact that GPI biosynthetic null mutants exhibit embryo lethality. Mutations in genes encoding specific GPl-anchored proteins （GAPs） further supports their contribution to diverse biological processes, occurring at the interface of the plasma membrane and cell wall, including signaling, cell wall metabolism, cell wall polymer cross-linking, and plasmodesmatal transport. Here, we review the literature concerning plant GPl-anchored proteins, in the context of their potential to act as molecular hubs that mediate interactions between the plasma membrane and the cell wall, and their potential to transduce the signal into the protoplast and, thereby, activate signal transduction pathways.
基金
supported by the ARC Centre of Excellence in Plant Cell Walls grant (CE1101007)
supported by a postdoctoral fellowship from the Philomathia Foundation
