Arabinogalactan protein
Arabinogalactan protein (AGPs)
Arabinogalactan protein is a broad term applied to diverse class of cell surface glycoproteins present in plant cell walls.[1] It is heavily glycosylated, with only 2-10% comprising the protein region.The protein family has been earlier reported to contain O-linked glycans, whereas recent efforts employing mass spectrometry have revealed the presence of N-linked glycans as well within this protein family isolated from elongating cotton fiber cells.[2]
Structure of Arabinogalactan Protein (AGPs)
AGPs contains protein backbone of varied length (5-30kDa) with N-terminal secretory peptide followed by AGP, Fasciclin domains and a C-terminal glycosylphosphatidylinositol (GPI) lipid anchor site. In some plant cells, the length of the mature protein backbone is only 10-13 residues long and they are therefore called as Arabinogalactan peptides.[3] The protein backbone contains domain rich in hydroxyproline/proline, serine, alanine and glycine amino acids. The repeated occurrence of Alanine/Serine/Threonine-Proline stretch (glycomodules) and the presence of hydroxyproline suggests the sites for O-linked glycosylation and arabinogalactan modification. The O-linked glycan chains predominantly contain galactose, arabinose, rhamnose, mannose, galacturonic acid and/or glucuronic acids and have a relatively high degree of polymerization, with a structure similar to arabinogalactan II.[4]
Biological roles of AGPs
AGPs are known to be involved in many biological processes like cell division,[5] cell elongation,[6] cell death,[7] pattern formation,[8] maintenance of post embryonic pattern, vascular, gametophyte development, signalling, root-microbe interaction[9] etc.
References
- ↑ Seifert, Georg J.; Roberts, Keith (January 2, 2007). "The Biology of Arabinogalactan Proteins". Annual Review of Plant Biology 58 (1): 137–61. doi:10.1146/annurev.arplant.58.032806.103801.
- ↑ Kumar, Saravanan; Kumar, K; Pandey, P; Rajamani, V; Padmalatha, KV; Dhandapani, G; Kanakachari, M; Leelavathi, S; Kumar, PA; Reddy, VS (December 1, 2013). "Glycoproteome of elongating cotton fiber cells.". Molecular & cellular proteomics : MCP 12 (12): 3677–89. doi:10.1074/mcp.M113.030726. PMID 24019148.
- ↑ Schultz, CJ; Johnson, KL; Currie, G; Bacic, A (September 2000). "The classical arabinogalactan protein gene family of arabidopsis.". The Plant cell 12 (9): 1751–68. doi:10.1105/tpc.12.9.1751. PMID 11006345.
- ↑ McNeil M, Darvill AG, Fry SC, Albersheim P. (1984) Structure and function of primary cell walls of plants. Anna Rev Biochem 53:625-663
- ↑ Serpe, Marcelo D.; Nothnagel, Eugene A. "Effects of Yariv phenylglycosides onRosa cell suspensions: Evidence for the involvement of arabinogalactan-proteins in cell proliferation". Planta 193 (4): 542–550. doi:10.1007/BF02411560.
- ↑ van Hengel, AJ; Roberts, K (October 2002). "Fucosylated arabinogalactan-proteins are required for full root cell elongation in arabidopsis.". The Plant journal : for cell and molecular biology 32 (1): 105–13. doi:10.1046/j.1365-313x.2002.01406.x. PMID 12366804.
- ↑ Gao, Minggeng; Showalter, Allan M. "Yariv reagent treatment induces programmed cell death in Arabidopsis cell cultures and implicates arabinogalactan protein involvement". The Plant Journal 19 (3): 321–331. doi:10.1046/j.1365-313X.1999.00544.x.
- ↑ Knox, JP; Linstead, PJ; Peart, J; Cooper, C; Roberts, K (November 1991). "Developmentally regulated epitopes of cell surface arabinogalactan proteins and their relation to root tissue pattern formation.". The Plant journal : for cell and molecular biology 1 (3): 317–26. doi:10.1046/j.1365-313X.1991.t01-9-00999.x. PMID 21736649.
- ↑ Nguema-Ona, Eric; Vicré-Gibouin, Maïté; Cannesan, Marc-Antoine; Driouich, Azeddine. "Arabinogalactan proteins in root–microbe interactions". Trends in Plant Science 18 (8): 440–449. doi:10.1016/j.tplants.2013.03.006.