MOLECULAR-CLONING AND NUCLEOTIDE-SEQUENCE OF CDNA FOR SPORAMIN, THE MAJOR SOLUBLE-PROTEIN OF SWEET-POTATO TUBEROUS ROOTS
MOLECULAR-CLONING AND NUCLEOTIDE-SEQUENCE OF CDNA FOR SPORAMIN, THE MAJOR SOLUBLE-PROTEIN OF SWEET-POTATO TUBEROUS ROOTS
复制标题
DOI：
10.1007/bf00020629
复制
发表时间：
1985-01-01
影响因子：
5.1
通讯作者：
ASAHI, T
中科院分区：
文献类型：
--
作者：
HATTORI, T;NAKAGAWA, T;ASAHI, T
在甘薯块根中，孢囊素的含量占总可溶性蛋白的80%以上，但在同一种植物的其他组织中含量很少。小麦胚芽提取液中块根RNA组分的体外翻译和抗孢子胺抗体的免疫沉淀表明，该蛋白是由膜结合的多聚体作为比成熟蛋白大4000道尔顿的前体合成的。用载体-引物法从块茎根总Poly(A)+RNA中构建了一个表达文库，并通过直接免疫学筛选获得了一个基本上全长的孢子胺基因克隆。Northern杂交分析表明，该基因全长约950个核苷酸，仅在块茎状根中特异表达，而在叶片、叶柄和非块茎中几乎不表达。该基因的核苷酸序列在成熟蛋白的氨基末端延伸了37个氨基酸。
Sporamin accounts for more than 80% of the total soluble proteins of tuberous roots of sweet potato, but very little, if any, in other tissues of the same plant. In vitro translation of RNA fractions from the tuberous roots in wheat germ extract and subsequent immunoprecipitation with the antibody to sporamin indicated that this protein is synthesized by membrane-bound polysomes as a precursor 4000 daltons larger than the mature protein. A cDNA expression library was constructed from the total poly(A)+RNA from the tuberous roots by a vector-primer method, and an essentially full-length cDNA clone for the sporamin mRNA was selected by direct immunological screening of the colonies. Northern blot analysis showed that sporamin mRNA is approximately 950 nucleotides in length and is specifically present in tuberous roots and very little, if any, in leaves, petioles and non-tuberous roots. Nucleotides sequence of the cDNA pedicts a 37 amino acid extension in the precursor at the amino-terminus of the mature protein.