RRC ID 595
Author Liepman AH, Wilkerson CG, Keegstra K.
Title Expression of cellulose synthase-like (Csl) genes in insect cells reveals that CslA family members encode mannan synthases.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract Glucuronoarabinoxylan, xyloglucan, and galactomannan are noncellulosic polysaccharides found in plant cell walls. All consist of beta-linked glycan backbones substituted with sugar side chains. Although considerable progress has been made in characterizing the structure of these polysaccharides, little is known about the biosynthetic enzymes that produce them. Cellulose synthase-like (Csl) genes are hypothesized to encode Golgi-localized beta-glycan synthases that polymerize the backbones of noncellulosic polysaccharides. To investigate this hypothesis, we used heterologous expression in Drosophila Schneider 2 (S2) cells to systematically analyze the functions of the gene products of a group of Csl genes from Arabidopsis and rice (Oryza sativa L.), including members from five Csl gene families (CslA, CslC, CslD, CslE, and CslH). Our analyses indicate that several members of the CslA gene family encode beta-mannan synthases. Recombinant CslA proteins produce beta-linked mannan polymers when supplied GDP-mannose. The same proteins can produce beta-linked glucomannan heteropolymers when supplied both GDP-mannose and GDP-glucose. One CslA protein also produced beta-linked glucan polymers when supplied GDP-glucose alone. Heterologous expression studies of additional candidate glycan synthases in insect cells or other systems may help identify other noncellulosic polysaccharide biosynthetic enzymes.
Volume 102(6)
Pages 2221-6
Published 2005-2-8
DOI 10.1073/pnas.0409179102
PII 0409179102
PMID 15647349
PMC PMC548565
MeSH Animals Cell Line Glucosyltransferases* / genetics Glucosyltransferases* / metabolism Insecta Mannosyltransferases* / genetics Mannosyltransferases* / metabolism Molecular Sequence Data Plant Proteins* / genetics Plant Proteins* / metabolism Polysaccharides / chemistry Polysaccharides / metabolism Recombinant Proteins / genetics Recombinant Proteins / metabolism Transgenes
IF 9.504
Times Cited 176
Arabidopsis / Cultured plant cells, genes pda12888 pda05367 pda02771 pda06746 pda04773 pda02081 pda05727