Oligomerization of the reversibly glycosylated polypeptide: its role during rice plant development and in the regulation of self-glycosylation

Not Just a Simple Sugar: Arabinose Metabolism and Function in Plants

Growth, development, structure as well as dynamic adaptations and remodeling processes in plants are largely controlled by properties of their cell walls. These intricate wall structures are mostly made up of different sugars connected through specific glycosidic linkages but also contain many glycosylated proteins. A key plant sugar that is present throughout the plantae, even before the divergence of the land plant lineage, but is not found in animals, is l-arabinose (l-Ara). Here, we summarize and discuss the processes and proteins involved in l-Ara de novo synthesis, l-Ara interconversion, and the assembly and recycling of l-Ara-containing cell wall polymers and proteins. We also discuss the biological function of l-Ara in a context-focused manner, mainly addressing cell wall-related functions that are conferred by the basic physical properties of arabinose-containing polymers/compounds. In this article we explore these processes with the goal of directing future research efforts to the many exciting yet unanswered questions in this research area.

Coimmunoprecipitation of reversibly glycosylated polypeptide with sucrose synthase from developing castor oilseeds

The sucrose synthase (SUS) interactome of developing castor oilseeds (COS; Ricinus communis) was assessed using coimmunoprecipitation (co-IP) with anti-(COS RcSUS1)-IgG followed by proteomic analysis. A 41-kDa polypeptide (p41) that coimmunoprecipitated with RcSUS1 from COS extracts was identified as reversibly glycosylated polypeptide-1 (RcRGP1) by LC-MS/MS and anti-RcRGP1 immunoblotting. Reciprocal Far-western immunodot blotting corroborated the specific interaction between RcSUS1 and RcRGP1. Co-IP using anti-(COS RcSUS1)-IgG and clarified extracts from other developing seeds as well as cluster (proteoid) roots of white lupin and Harsh Hakea consistently recovered 90 kDa SUS polypeptides along with p41/RGP as a SUS interactor. The results suggest that SUS interacts with RGP in diverse sink tissues to channel UDP-glucose derived from imported sucrose into hemicellulose and/or glycoprotein/glycolipid biosynthesis.