Microtubules are filamentous structures necessary for cell division, motility and morphology, with dynamics critically regulated by microtubule-associated proteins (MAPs). Here we outline the molecular mechanism by which the MAP, COMPANION OF CELLULOSE SYNTHASE1 (CC1), controls microtubule bundling and dynamics to sustain plant growth under salt stress. CC1 contains an intrinsically disordered N-terminus that links microtubules at evenly distributed points through four conserved hydrophobic regions.
View Article and Find Full Text PDF-glycosylation is one of the most common protein post-translational modifications in eukaryotes and has a relatively conserved core structure between fungi, animals and plants. In plants, the biosynthesis of -glycans has been extensively studied with all the major biosynthetic enzymes characterized. However, few studies have applied advanced mass spectrometry to profile intact plant -glycopeptides.
View Article and Find Full Text PDFThe Golgi apparatus (GA) is a crucial organelle in the biosynthesis of non-cellulosic polysaccharides, glycoproteins and proteoglycans that are primarily destined for secretion to the cell surface (plasma membrane, cell wall and apoplast). Only a small proportion of the proteins involved in these processes have been identified in plants, with the majority of their functions still unknown. The availability of a GA proteome would greatly assist plant biochemists, cell and molecular biologists in determining the precise function of the cell wall-related proteins.
View Article and Find Full Text PDFThe analysis of post-translational modifications (PTMs) by proteomics is regarded as a technically challenging undertaking. While in recent years approaches to examine and quantify protein phosphorylation have greatly improved, the analysis of many protein modifications, such as glycosylation, are still regarded as problematic. Limitations in the standard proteomics workflow, such as use of suboptimal peptide fragmentation methods, can significantly prevent the identification of glycopeptides.
View Article and Find Full Text PDFSalinity is one of the major abiotic stresses affecting plant productivity but surprisingly, a thorough understanding of the salt-responsive networks responsible for sustaining growth and maintaining crop yield remains a significant challenge. Rice suspension culture cells (SCCs), a single cell type, were evaluated as a model system as they provide a ready source of a homogenous cell type and avoid the complications of multicellular tissue types in planta. A combination of growth performance, and transcriptional analyses using known salt-induced genes was performed on control and 100 mM NaCl cultured cells to validate the biological system.
View Article and Find Full Text PDFBackground: The packaging, expression, and maintenance of nuclear genomes using histone proteins is a ubiquitous and fundamental feature of eukaryotic cells, yet the phylum Dinoflagellata has apparently abandoned this model of nuclear organization. Their nuclei contain permanently condensed, liquid crystalline chromosomes that seemingly lack histone proteins, and contain remarkably large genomes. The molecular basis for this reorganization is poorly understood, as is the sequence of evolutionary events that led to such radical change.
View Article and Find Full Text PDFUsing a series of multiplexed experiments we studied the quantitative changes in protein abundance of three Australian bread wheat cultivars (Triticum aestivum L.) in response to a drought stress. Three cultivars differing in their ability to maintain grain yield during drought, Kukri (intolerant), Excalibur (tolerant), and RAC875 (tolerant), were grown in the glasshouse with cyclic drought treatment that mimicked conditions in the field.
View Article and Find Full Text PDFThe pellicles of alveolates (ciliates, apicomplexans, and dinoflagellates) share a common organization, yet perform very divergent functions, including motility, host cell invasion, and armor. The alveolate pellicle consists of a system of flattened membrane sacs (alveoli, which are the defining feature of the group) below the plasma membrane that is supported by a membrane skeleton as well as a network of microtubules and other filamentous elements. We recently showed that a family of proteins, alveolins, are common and unique to this pellicular structure in alveolates.
View Article and Find Full Text PDFRice (Oryza sativa cv Taipei 309) suspension culture cells (SCCs) were used as a simple, single cell model system to gain insights into the complex abscisic acid (ABA) signaling response pathways in plants. Following system establishment involving morphological observations and transcript profiling of genes known to be ABA responsive in planta, a comprehensive proteomic and metabolomic study was performed. A total of 759 buffer-soluble proteins that included 3284 peptides categorized into 656 protein families are reported.
View Article and Find Full Text PDFTo identify integral and peripheral plasma membrane (PM) proteins from Oryza sativa (rice), highly enriched PM fractions from rice suspension cultured cells were analyzed using two complementary approaches. The PM was enriched using aqueous two-phase partitioning and high pH carbonate washing to remove soluble, contaminating proteins and characterized using enzymatic and immunological analyses. Proteins from the carbonate-washed PM (WPM) were analyzed by either one-dimensional gel electrophoresis (1D-SDS-PAGE) followed by tryptic proteolysis or proteolysis followed by strong cation exchange liquid chromatography (LC) with subsequent analysis of the tryptic peptides by LC-MS/MS (termed Gel-LC-MS/MS and 2D-LC-MS/MS, respectively).
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