Header

UZH-Logo

Maintenance Infos

The hydroxyproline-rich glycoprotein domain of the Arabidopsis LRX1 requires Tyr for function but not for insolubilization in the cell wall


Ringli, C (2010). The hydroxyproline-rich glycoprotein domain of the Arabidopsis LRX1 requires Tyr for function but not for insolubilization in the cell wall. The Plant Journal, 63(4):662-669.

Abstract

Summary Extensins, hydroxyproline-rich repetitive glycoproteins with Ser--Hyp4 motifs, are structural proteins in plant cell walls. The leucine-rich repeat extensin 1 (LRX1) of Arabidopsis thaliana is an extracellular protein with both a leucine-rich repeat and an extensin domain, and has been demonstrated to be important for cell-wall formation in root hairs. lrx1 mutants develop defective cell walls, resulting in a strong root hair phenotype. The extensin domain is essential for protein function and is thought to confer insolubilization of LRX1 in the cell wall. Here, in vivo characterization of the LRX1 extensin domain is described. First, a series of LRX1 extensin deletion constructs was produced that led to identification of a much shorter, functional extensin domain. Tyr residues can induce intra- and inter-molecular cross-links in extensins, and substitution of Tyr in the extensin domain by Phe led to reduced activity of the corresponding LRX1 protein. An additional function of Tyr (or Phe) is provided by the aromatic nature of the side chain. This suggests that these residues might be involved in hydrophobic stacking, possibly as a mechanism of protein assembly. Finally, modified LRX1 proteins lacking Tyr in the extensin domain are still insolubilized in the cell wall, indicating strong interactions of extensins within the cell wall in addition to the well-described Tyr cross-links.

Abstract

Summary Extensins, hydroxyproline-rich repetitive glycoproteins with Ser--Hyp4 motifs, are structural proteins in plant cell walls. The leucine-rich repeat extensin 1 (LRX1) of Arabidopsis thaliana is an extracellular protein with both a leucine-rich repeat and an extensin domain, and has been demonstrated to be important for cell-wall formation in root hairs. lrx1 mutants develop defective cell walls, resulting in a strong root hair phenotype. The extensin domain is essential for protein function and is thought to confer insolubilization of LRX1 in the cell wall. Here, in vivo characterization of the LRX1 extensin domain is described. First, a series of LRX1 extensin deletion constructs was produced that led to identification of a much shorter, functional extensin domain. Tyr residues can induce intra- and inter-molecular cross-links in extensins, and substitution of Tyr in the extensin domain by Phe led to reduced activity of the corresponding LRX1 protein. An additional function of Tyr (or Phe) is provided by the aromatic nature of the side chain. This suggests that these residues might be involved in hydrophobic stacking, possibly as a mechanism of protein assembly. Finally, modified LRX1 proteins lacking Tyr in the extensin domain are still insolubilized in the cell wall, indicating strong interactions of extensins within the cell wall in addition to the well-described Tyr cross-links.

Statistics

Citations

22 citations in Web of Science®
21 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

2 downloads since deposited on 30 Jan 2011
0 downloads since 12 months
Detailed statistics

Additional indexing

Contributors:Institute of Plant Biology, University of Zurich,
Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Plant and Microbial Biology
Dewey Decimal Classification:580 Plants (Botany)
Uncontrolled Keywords:leucine-rich repeat extensin 1, extensin, Tyr cross-linking, Arabidopsis, root hairs, cell wall
Language:English
Date:2010
Deposited On:30 Jan 2011 12:00
Last Modified:05 Apr 2016 14:39
Publisher:Wiley-Blackwell
ISSN:0960-7412
Publisher DOI:https://doi.org/10.1111/j.1365-313X.2010.04270.x
PubMed ID:20545889

Download