Functional diversity of the plant glycine-rich proteins superfamily

Abstract

The first plant glycine-rich proteins (GRPs) have been isolated more than 20 years ago based on their specific expression pattern and/or modulation by several biotic and abiotic factors. This superfamily is characterized by the presence of a glycine-rich domain arranged in (Gly)(n)-X repeats. The presence of additional motifs, as well as the nature of the glycine repeats, groups them in different classes. The diversity in structure as well as in expression pattern, modulation and sub-cellular localization have always indicated that these proteins, although classified as members of the same superfamily, would perform different functions in planta. Only now, two decades later, with the first functional characterizations of plant GRPs their involvement in diverse biological and biochemical processes are being uncovered. Here, we review the so far ascribed functions of plant GRPs.

Binding of G-quadruplexes to the N-terminal Recognition Domain of the RNA Helicase Associated with AU-rich Element (RHAU)

“…4). The specific role of the Gly-rich motif is unclear at this point, although these motifs have been observed proximal to single-stranded RNA recognition motifs to function in RNA binding (47). Connection of the RSM to the core helicase domain via a flexible linker (consistent with our inability to produce a stable RHAU truncation containing residues 151-209) would enable RSM-bound quadruplex to directly access the helicase active site.…”

Gene expression changes in response to drought stress in Ilex paraguariensis leaves

“…The diverse but highly specific expression pattern of GRP genes, when considered together with the distinct sub-cellular localization of some GRP groups, clearly indicates that these proteins are implicated in several independent physiological processes, including plant defence against biotic and abiotic stress (Bocca et al, 2005). Several GRPs are modulated by ABA and osmotic stress (Mangeon et al 2010). Furthermore, the RNA-binding activity of some GRPs (e.g.…”

Arabidopsis TRIGALACTOSYLDIACYLGLYCEROL5 Interacts with TGD1, TGD2, and TGD4 to Facilitate Lipid Transfer from the Endoplasmic Reticulum to Plastids

“…Proteins with semirepetitive glycine-rich motifs are often named glycine-rich proteins (GRPs), which are a large group of proteins found in organisms ranging from bacteria to humans (Sachetto-Martins et al, 2000). Plant GRPs are diverse in terms of glycine domain organization, structure, function, subcellular localization, and expression pattern and modulation of their genes (Sachetto-Martins et al, 2000;Mangeon et al, 2010). Although the role of the glycine-rich domain present in the vast majority of GRPs remains obscure, it is widely believed that GRPs are part of multicomponent complexes where glycine-rich sequences are necessary for sustaining stability and conformational flexibility of protein-protein and protein-nucleic acid interactions (Sachetto-Martins et al, 2000;Mousavi and Hotta, 2005;Fusaro and Sachetto-Martins, 2007;Mangeon et al, 2010).…”

“…Plant GRPs are diverse in terms of glycine domain organization, structure, function, subcellular localization, and expression pattern and modulation of their genes (Sachetto-Martins et al, 2000;Mangeon et al, 2010). Although the role of the glycine-rich domain present in the vast majority of GRPs remains obscure, it is widely believed that GRPs are part of multicomponent complexes where glycine-rich sequences are necessary for sustaining stability and conformational flexibility of protein-protein and protein-nucleic acid interactions (Sachetto-Martins et al, 2000;Mousavi and Hotta, 2005;Fusaro and Sachetto-Martins, 2007;Mangeon et al, 2010). Indeed, the glycine-rich motif of several bacterial and mammalian GRPs has been shown to be essential for physically associating with their interacting partners to form functional protein complexes (Lau et al, 1997;Suzuki et al, 1998;Friesen and Dreyfuss, 2000;Terasawa et al, 2006).…”