水稻半纤维素支链合酶基因GT61家族的结构特征和组织表达分析

从生物信息学和基因表达的角度,鉴定OsGT61家族成员的结构特征和组织表达特性。结果表明,OsGT61家族含有25个成员,分为3个亚类。A、B和C亚类分别含有19、3和3个成员,其基因的外显子数介于1~7个。其蛋白质大小为49.1~73.8ku,pI为5.4~10.4。该家族蛋白质的C端motif较为保守。而且,它们含有Ser/Thr激酶的磷酸化位点分别为9~29个和3~13个,Tyr激酶的磷酸化位点小于7个。但是,该家族成员的糖基化位点相对较少,16个成员存在1~4个O-糖基化位点,3个蛋白存在1~2个N-糖基化位点。基因表达芯片聚类分析和半定量RT-PCR检测表明,OsGT61基因家族主要成员在不同组织中表达水平存在明显差异。这些结果暗示OsGT61家族基因在水稻不同组织中细胞壁半纤维素生物合成中发挥不同作用。

Bioinformatics and expression analysis of OsGT61 family genes involved in hemicellulose side chain biosynthesis in rice

Arabinoxylan (AX) is the major hemicellulose in cell wall of monocot plants,and plays an important role in cell wall biosynthesis with potential dietary and biomass applications.Glycosyltransferase 61 (GT61) protein family has been reported to involve in AX side chain elongation in grasses.Based on bioinformatics analysis and expression profiling,the gene structures and expression patterns of OsGT61 family members were observed in this study.As a result,a total of 25 OsGT61 genes were divided into 3 subclasses.Subclass A,B and C contain 19,3 and 3 genes,respectively.The numbers of exons in GT61 family varied from 1 to 7,and the encoded proteins had molecular weights between 49.1 and 73.8 ku,with the pI ranging from 5.4 to 10.4.In particular,the C-terminal motif was conserved in these proteins of OsGT61 family.Furthermore,the Ser/thr phosphorylation sites were respectively located on the 9-29 residues and 3-13 residues,and the maximum Tyr phosphorylation sites were seven.The OsGT61 family had less glycosylation sites,e.g.,16 members had O-glycosylation sites from 1 to 4,and only 3 members contained 1 or 2 N-glycosylation sites.Phylogenetic analysis showed that OsGT61 family displayed distinct expression patterns in different stages,and 10 representative genes expression levels were verified by RT-PCR.Hence,these data indicated that OsGT61 family may play different roles in the hemicelluloses biosynthesis in rice and beyond.