CHARACTERIZATION OF MESSENGER-RNA FOR A PROLINE-RICH PROTEIN OF COTTON FIBER
CHARACTERIZATION OF MESSENGER-RNA FOR A PROLINE-RICH PROTEIN OF COTTON FIBER
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DOI：
10.1104/pp.108.2.669
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发表时间：
1995-06-01
期刊：
影响因子：
7.4
通讯作者：
KELLER, G
中科院分区：
文献类型：
--
作者：
JOHN, ME;KELLER, G
棉花（Gossypium hirsutum L.）mRNA（H6）主要在纤维细胞中表达，并且在早期初生细胞壁形成期间存在。然而，发现H6蛋白在后期阶段积累，当活跃的次生细胞壁形成发生时，表明可能在翻译水平上的调节和在次生细胞壁组装中的功能。pCK-H6的核苷酸衍生氨基酸序列富含脯氨酸（35 mol %），计算分子量为21 kD。棉花蛋白H6含有丙氨酸（丝氨酸）-苏氨酸（丝氨酸）-脯氨酸的重复五聚体基序（17）。其氨基酸组成和溶解性表明其可能属于阿拉伯半乳聚糖蛋白质。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（55 kD）和尺寸排阻色谱法（77-83 kD）高估了体外合成的H6蛋白的大小相比，来自核苷酸序列的分子量（21 kD）。由其不寻常的一级结构决定的分子构象可能是其异常迁移率的原因。富含脯氨酸的阿拉伯半乳聚糖型蛋白质在棉纤维中的存在提出了一种有趣的可能性，即它可能是质膜的一个组成部分，参与棉纤维次生壁的发育和结构。
Cotton (Gossypium hirsutum L.) mRNA (H6) is expressed predominantly in fiber cells and is present during early primary cell wall formation. However, H6 protein is found to accumulate during later stages, when active secondary cell wall formation occurs, indicating possible regulation at the translational level and function in the secondary cell wall assembly. The nucleotide-derived amino acid sequence of pCK-H6 is proline rich (35 mol %) with a calculated molecular mass of 21 kD. Cotton protein H6 contains a repetitive pentameric motif (17) of alanine (serine)-threonine (serine)-proline-proline-proline. Its amino acid composition and solubility indicate that it may belong to the group of arabinogalactan proteins. Both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (55 kD) and size-exclusion chromatography (77-83 kD) overestimated the size of in vitro synthesized H6 protein compared to the molecular mass derived from the nucleotide sequence (21 kD). The conformation of the molecule determined by its unusual primary structure may be the cause of its anomalous mobility. The presence of a proline-rich, arabinogalactan-type protein in cotton fiber raises the interesting possibility that it may be an integral part of the plasmalemma taking part in the development and architecture of the secondary wall of cotton fiber.