Arabinogalactan-proteins (AGPs) are cell wall proteoglycans widely distributed in the plant kingdom. They are thought to have important roles in various aspects of plant growth and development. AGPs are divided into two classes depending upon their core protein: 'classical' and 'nonclassical' AGPs. Classical AGPs contain hydroxyproline (Hyp), Ala, Ser, Thr and Gly as the major amino acid constituents []. This entry represents a group of classical arabinogalactan proteins, including AGP1/2/3/4/5/7/10 from Arabidopsis [, ].
This entry consists of AGP19 from Arabidopsis and related proteins. AGP19 is a member of the lysine-rich arabinogalactan protein (AGP) subfamily within the hydroxyproline-rich glycoprotein (HRGP) superfamily. AGPs are hyperglycosylated proteins implicated in different aspects of plant growth and development. Protein backbones of AGPs are rich in Pro/Hyp (hydroxyproline), Ser, Ala and Thr and are modified by the addition of type II arabinogalactan polysaccharides and arabinose oligosaccharides to Hyp residues []. AGP19, as the other lysine-rich members AGP17 and AGP18, contains a C-terminal lysine-rich region and is thought to be related to sexual reproduction in flowering plants [, ].
This entry represents a subgroup of plant lysine-rich arabinogalactan proteins, including AGP9/17/18 from Arabidopsis. They are members of the lysine-rich arabinogalactan protein (AGP) subfamily within the hydroxyproline-rich glycoprotein (HRGP) superfamily. AGPs are hyperglycosylated proteins implicated in different aspects of plant growth and development. Protein backbones of AGPs are rich in Pro/Hyp (hydroxyproline), Ser, Ala and Thr and are modified by the addition of type II arabinogalactan polysaccharides and arabinose oligosaccharides to Hyp residues []. They are predicted to contain the glycosylphosphatidylinositol (GPI) anchor and are localized to the plasma membrane. AtAGP18 is involved in a signal transduction pathway regulating plant growth and development [].
