茶树果胶乙酰酯酶家族成员的鉴定和生物信息学分析

茶树是氟的超富集植物,叶片高氟含量与人体健康密切相关。果胶乙酰酯酶（PAE）可能通过调控果胶的去乙酰化作用参与茶树叶片对氟的富集和解毒,然而目前并无茶树PAEs的相关报道。本研究以茶树舒茶早基因组和三代测序数据为基础,利用生物信息学的方法开展了PAEs的鉴定及其特性、进化和定位分析。结果表明,在茶树中,PAE家族有12个蛋白,属于PAE5、PAE8、PAE9、PAE10、PAE12等5个成员,具有CLDG、PxYH、GGGWC、GS、NWN、rYCDG、GCSAG、NaAYDSWQ、HCQ等9个保守基序;在进化关系上,茶树PAEs与葡萄、可可亲缘关系较近;12个CsPAEs氨基酸大小为326~515,分子量为36.7~56.9βkDa,等电点为5.1~8.9;除CsPAE5、CsPAE5-1定位线粒体,CsPAE10-1可能定位胞质外,其他9个CsPAEs定位细胞壁;CsPAE5、CsPAE5-1、CsPAE12和CsPAE12-1为跨膜蛋白。此研究结果将为解析PAE在茶树叶片氟富集和解毒过程中的功能奠定基础。

Identification and Bioinformatic Analysis of Pectin Acetylesterases from Tea Plant

Tea plant is a fluoride hyperaccumulator with high fluoride in leaves, which has many health benefits to human body. Tea pectin acetylesterase (PAE) may be related to fluoride accumulation and detoxification by regulating pectin deacytelation. However, few reports on tea PAEs were available. In the study, the identification and analysis of characteristic, evolutionary and subcellular localization of CsPAEs were performed by bioinformatics method based on tea genome database and three next-generation sequencing data of Camellia sinensis var. sinensis cv ‘Shuchazao’. The results indicate that 12 CsPAEs belonged to five members, including PAE5, PAE8, PAE9, PAE10 and PAE12. Nine conserved motifs including CLDG, PxYH, GGGWC, GS, NWN, rYCDg, GCSAG, NaAYDSWQ and HCQ were found in CsPAEs; CsPAEs were more closely related to PAEs of Vitis vinifera and Theobroma cacao according to evolutionary relationship; Amino acid length, molecular weight and theoretical isoelectric point of 12 CsPAEs varies from 326-515, 36.7-56.9βkDa and 5.1-8.9, respectively. Except that CsPAE5 and CsPAE5-1 were predicated to be localized in the mitochondrion, and CsPAE10-1 might be present in cellular martix. The rest CsPAEs were predicated to be localized in the cell wall. CsPAE5, CsPAE5-1, CsPAE12 and CsPAE12-1 were transmembrane proteins. The results provided a foundation for functional analysis of CsPAEs involved in fluoride accumulation and detoxification.