The Cellulose Synthase Superfamily
Year: 2000
Type: article
Abstract: The availability of a nearly complete genome sequence for Arabidopsis has created many novel opportunities to identify, by computational methods, the genes that encode enzymes, which have been difficult to characterize by conventional means. We have used this approach to identify a large family of genes of unknown function that show sequence similarity to cellulose synthase. Our working hypothesis is that these genes encode enzymes that catalyze the synthesis of non-cellulosic polysaccharides (Cutler and Somerville, 1997). A recent breakthrough in research concerning the biogenesis of plant cell walls was the identification, by genomic methods, of genes encoding cellulose synthase in cotton fibers (Pear et al., 1996;Delmer, 1999). The cotton cellulose synthase genes, now termedCesA1 and CesA2, were identified in a collection of expressed sequence tag (EST) sequences on the basis of weak sequence similarity to genes for cellulose synthase from bacteria. In addition, the genes were expressed at high levels in cotton fibers at the onset of secondary wall synthesis and a purified fragment of one of the corresponding proteins was shown to bind UDP-Glc, the proposed substrate for cellulose biosynthesis. The conclusion that the cottonCesA genes are cellulose synthases is supported by results obtained with two cellulose-deficient Arabidopsis mutants,rsw1 (Arioli et al., 1998) and irx3 (Turner and Somerville, 1997; Taylor et al., 1999). The genes corresponding to the RSW1 and IRX3 loci exhibit a high degree of sequence similarity to the cotton CesA genes and are considered orthologs. Ten full-length CesA genes have been sequenced from Arabidopsis, and there is a genome survey sequence that may indicate one additional family member (Fig.1).
Source: PLANT PHYSIOLOGY
DOI: 10.1104/pp.124.2.495
Authors: Todd A. Richmond, Chris R. Somerville
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2122676114