Disease relevance of AGP1

• Characterization of the Arabidopsis lysine-rich arabinogalactan-protein AtAGP17 mutant (rat1) that results in a decreased efficiency of agrobacterium transformation [1].

High impact information on AGP1

• We have used a combination of enhancer detection tagging and RNA interference (RNAi)-induced posttrancriptional silencing to demonstrate that AGP18, a gene encoding a classical arabinogalactan protein, is essential for female gametogenesis in Arabidopsis thaliana [2].
• A classical arabinogalactan protein is essential for the initiation of female gametogenesis in Arabidopsis [2].
• The predicted SOS5 protein contains an N-terminal signal sequence for plasma membrane localization, two arabinogalactan protein-like domains, two fasciclin-like domains, and a C-terminal glycosylphosphatidylinositol lipid anchor signal sequence [3].
• In contrast, localization of epitopes associated with xyloglucan or arabinogalactan was similar in wild-type and emb30 tissues, and the localization of a marker molecule to vacuoles appeared normal [4].
• Recombinant At-P4H-2 hydroxylated poly(L-proline) and extensin and arabinogalactan-like peptides effectively but with much higher Km values than At-P4H-1, suggesting different roles for the two At-P4Hs in the plant cell [5].

Biological context of AGP1

• Yariv reagent treatment induces programmed cell death in Arabidopsis cell cultures and implicates arabinogalactan protein involvement [6].
• The additional gene families and functional groups enriched in the root-hair morphogenesis transcriptome are cell wall enzymes, hydroxyproline-rich glycoproteins (extensins) and arabinogalactan proteins, peroxidases, receptor-like kinases and proteins with predicted glycosylphosphatidylinositol (GPI) anchors [7].
• A surprising finding was that over 40% of the proteins identified here have probable AG glycosylation modules, suggesting that AG glycosylation of cell surface proteins is widespread [8].
• We used the biased amino acid composition of AGPs to identify AGPs and arabinogalactan (AG) peptides in the Arabidopsis genome [9].
• Analysis of the amino acid sequences of two novel AGP-like proteins from Arabidopsis predicts that these proteins contain consensus signals for GPI-anchor addition [10].

Anatomical context of AGP1

• AtAGP30, an arabinogalactan-protein in the cell walls of the primary root, plays a role in root regeneration and seed germination [11].
• The reb1-1 mutation of Arabidopsis alters the morphology of trichoblasts, the expression of arabinogalactan-proteins and the organization of cortical microtubules [12].
• As the peripheral convoluted sheets accumulate callose and arabinogalactan proteins, they are converted into stub-like projections, which grow centripetally, i.e. toward the interior of the syncytium, fusing with the wide tubular networks already assembled in the division plane [13].

Associations of AGP1 with chemical compounds

• The RHD1 isoform is specifically required for the galactosylation of xyloglucan (XG) and type II arabinogalactan (AGII) but is not involved either in D-galactose detoxification or in galactolipid biosynthesis [14].
• Characterization of synthetic hydroxyproline-rich proteoglycans with arabinogalactan protein and extensin motifs in Arabidopsis [15].
• The expression patterns of arabinogalactan-protein AtAGP30 and GLABRA2 reveal a role for abscisic acid in the early stages of root epidermal patterning [16].
• This mutation leads to a 50% reduction in the monosaccharide L-arabinose in most organs and affects arabinose-containing pectic cell wall polysaccharides and arabinogalactan proteins [17].
• The lysine-rich arabinogalactan-protein subfamily in Arabidopsis: gene expression, glycoprotein purification and biochemical characterization [18].

Other interactions of AGP1

• MBP2 contains a region of high content of proline and alanine residues, commonly found in arabinogalactan proteins and hydroxyproline-rich glycoproteins [19].
• Hydroxyproline (Hyp) glycoside profiles of GFP-AtAGP17 in conjunction with the deduced protein sequence also served to corroborate the Hyp contiguity hypothesis, which predicts contiguous Hyp residues as attachment sites for arabinosides and clustered, non-contiguous Hyp residues as attachment sites for arabinogalactan polysaccharides [18].
• The polypeptide backbone of xylogen is a hybrid-type molecule with properties of both arabinogalactan proteins and nonspecific lipid-transfer proteins [20].

Analytical, diagnostic and therapeutic context of AGP1

• AGP was shown to be a constituent of wild-type floral abscission zones during and soon after cell separation had been completed [21].
• Binding of arabinogalactan proteins by Yariv phenylglycoside triggers wound-like responses in Arabidopsis cell cultures [22].
• The expression of "classical" arabinogalactan protein genes in pollen tubes of Arabidopsis thaliana was characterized by RT-PCR [23].

References