A relaxed specificity in interchain disulfide bond formation characterises the assembly of a low-molecular-weight glutenin subunit in the endoplasmic reticulum
Author(s)
Lombardi, Alessio
Barbante, Alessandra
Della Cristina, Pietro
Rosiello, Daniele
Castellazzi, Chiara Lara
Date Issued
2009
Type
Article
Abstract
Wheat (Triticum aestivum) grains contain large protein polymers constituted by two main classes of polypeptides: the highmolecular-
weight glutenin subunits and the low-molecular-weight glutenin subunits (LMW-GS). These polymers are among
the largest protein molecules known in nature and are the main determinants of the superior technological properties of wheat
flours. However, little is known about the mechanisms controlling the assembly of the different subunits and the way they are
arranged in the final polymer. Here, we have addressed these issues by analyzing the formation of interchain disulfide bonds
between identical and different LMW-GS and by studying the assembly of mutants lacking individual intrachain disulfides.
Our results indicate that individual cysteine residues that remain available for disulfide bond formation in the folded
monomer can form interchain disulfide bonds with a variety of different cysteine residues present in a companion subunit.
These results imply that the coordinated expression of many different LMW-GS in wheat endosperm cells can potentially lead
to the formation of a large set of distinct polymeric structures, in which subunits can be arranged in different configurations. In
addition, we show that not all intrachain disulfide bonds are necessary for the generation of an assembly-competent structure
and that the retention of a LMW-GS in the early secretory pathway is not dependent on polymer formation.
Additional information
L'articolo รจ disponibile sul sito dell'editore: http://www.aspb.org
Citation
Lombardi A. et al. 2009. A relaxed specificity in interchain disulfide bond formation characterises the assembly of a low-molecular-weight glutenin subunit in the endoplasmic reticulum. "Plant Physiology" 149(1): 412-423
File(s)![Thumbnail Image]()
Name
Lombardi et al Plant Physiol 2009.pdf
Size
33.04 KB
Format
Adobe PDF
Checksum (MD5)
6e687f302437c80abf9b79de7a476f52