柑橘果实成熟特异基因CsPMEI/InvI的克隆与序列分析

摘要

Fruit-ripening-specific expression genes play important roles on the regulation of fruit ripening and quality formation.A full-length cDNA of fruit ripening-specific gene,designated as CsPEMI/InvI (GenBank accession No.KC198084),was isolated from Newhall navel orange (Citrus sinensis ‘Newhall’) by RT-PCR and RACE.The full-length of CsPMEI/InvI was 945 bp,containing an open reading frame of 618 bp and encoding 205 amino acids.The molecular formula of encoded protein was C977H1568N296O282S10 with a calculated molecular of 22.29 kDa and an isoelectric point of 9.84.The encoded protein belonged to InvI/PMEI family including highly-conserved Cys residue in the protein sequence,one cAMP and cGMP-dependent protein kinase phosphorylation site,three protein kinase C phosphorylation sites,two casein kinase Ⅱ phosphorylation sites and three N-myristoylation sites.In its secondary structure,α-helix was the main structural conformation.%果实成熟特异基因对于调控果实成熟及其品质形成具有重要的作用.在前期获得柑橘Citrus果实成熟特异基因片段的基础上,以纽荷尔脐橙Citrus sinensis ‘Newhall’成熟果实为试材,应用RT-PCR和RACE技术,分离获得果实成熟特异基因的cDNA全长序列,命名为Cs PMEI/InvI,GenBank登录号:KC 198084；生物信息学分析表明:该基因全长945 bp,包含618 bp完整的开放阅读框,编码205个氨基酸,其编码的蛋白质分子式为C977H1568N296O282S10,相对分子量为22.29 kDa,理论等电点为9.84,属于InvI/PMEI(转化酶抑制子/果胶甲酯酶抑制子)家族成员,含有该家族严格保守的Cys残基,存在1个cAMP和cGMP-蛋白激酶磷酸化位点、3个蛋白激酶C磷酸化位点、2个酪蛋白激酶Ⅱ磷酸化位点和3个N-酰基化位点,其二级结构主要以α-螺旋为主.Cs PMEI/InvI基因的分离为进一步研究柑橘果实的成熟机制提供了基础.