Y. Gaspar et al., The complex structures of arabinogalactan-proteins and the journey towardsunderstanding function, PLANT MOL B, 47(1-2), 2001, pp. 161-176
Arabinogalactan-proteins (AGPs) are a family of complex proteoglycans found
in all higher plants. Although the precise function(s) of any single AGP i
s unknown, they are implicated in diverse developmental roles such as diffe
rentiation, cell-cell recognition, embryogenesis and programmed cell death.
DNA sequencing projects have made possible the identification of the genes
encoding a large number of putative AGP protein backbones. In contrast, ou
r understanding of how AGPs undergo extensive post-translational modificati
on is poor and it is important to understand these processes since they are
likely to be critical for AGP function. Genes believed to be responsible f
or post-translational modification of an AGP protein backbone, include prol
yl hydroxylases, glycosyl transferases, proteases and glycosylphosphatidyli
nositol-anchor synthesising enzymes. Here we examine models for proteoglyca
n function in animals and yeast to highlight possible strategies for determ
ining the function(s) of individual AGPs in plants.