A relaxed specificity in interchain disulfide bond formation characterizes the assembly of a low-molecular-weight glutenin bubunit in the endoplasmic reticulum
Lombardi, Alessio, Barbante, Alessandra, Della Cristina, Pietro, Rosiello, Daniele, Castellazzi, Chiara Lara, Sbano, L., Masci, Stefania and Ceriotti, Aldo. (2009) A relaxed specificity in interchain disulfide bond formation characterizes the assembly of a low-molecular-weight glutenin bubunit in the endoplasmic reticulum. Plant Physiology, Vol.149 (No.1). pp. 412-423. ISSN 0032-0889Full text not available from this repository.
Official URL: http://dx.doi.org/10.1104/pp.108.127761
Wheat (Triticum spp.) grains contain large protein polymers constituted by two main classes of polypeptides: the high-molecular-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.
|Item Type:||Journal Article|
|Subjects:||S Agriculture > SB Plant culture|
|Divisions:||Faculty of Science > Mathematics|
|Journal or Publication Title:||Plant Physiology|
|Publisher:||American Society of Plant Biologists|
|Number of Pages:||12|
|Page Range:||pp. 412-423|
|Access rights to Published version:||Open Access|
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