Datta K, Schmidt A, Marcus A
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111.
Plant Cell. 1989 Sep;1(9):945-52. doi: 10.1105/tpc.1.9.945.
We have resolved and analyzed two proline-rich proteins isolated from the walls of soybean cells in culture. The proteins are similar in amino acid content, containing 20% proline, 20% hydroxyproline, 20% lysine, 16% valine, 10% tyrosine, and 10% glutamate. The proteins undergo a rearrangement or a limited cleavage in dilute NaOH, but are otherwise remarkably stable to a high concentration of alkali. We have cloned and sequenced a cDNA from soybean axes germinated for 31 hours (1A10-2) coding for a protein that closely corresponds in its amino acid content to that of the proline-rich proteins. The cDNA sequence predicts a decameric repeat of Pro-Pro-Val-Tyr-Lys-Pro-Pro-Val-Glu-Lys. Consequently, this class of proteins is referred to as repetitive proline-rich proteins, i.e., RPRP2 and RPRP3. We have also analyzed RNA gel blots with probes that discriminate between the new cDNA clone and a related cDNA previously reported [SbPRP1; Hong, Nagao, and Key (1987). J. Biol. Chem. 262, 8367-8376]. Messenger RNAs from young seedlings and from soybean suspension cultures correspond primarily to the new RPRP clone (1A10-2), whereas the predominant mRNA accumulating later in the roots corresponds to SbPRP1.
我们已经解析并分析了从培养的大豆细胞壁中分离出的两种富含脯氨酸的蛋白质。这两种蛋白质的氨基酸含量相似，含有20%的脯氨酸、20%的羟脯氨酸、20%的赖氨酸、16%的缬氨酸、10%的酪氨酸和10%的谷氨酸。这些蛋白质在稀氢氧化钠中会发生重排或有限的裂解，但在其他情况下对高浓度碱具有显著的稳定性。我们从萌发31小时的大豆轴中克隆并测序了一个cDNA（1A10 - 2），其编码的蛋白质在氨基酸含量上与富含脯氨酸的蛋白质非常相似。该cDNA序列预测了一个由脯氨酸 - 脯氨酸 - 缬氨酸 - 酪氨酸 - 赖氨酸 - 脯氨酸 - 脯氨酸 - 缬氨酸 - 谷氨酸 - 赖氨酸组成的十聚体重复序列。因此，这类蛋白质被称为富含脯氨酸的重复蛋白，即RPRP2和RPRP3。我们还使用能够区分新的cDNA克隆和先前报道的相关cDNA [SbPRP1；Hong、Nagao和Key（1987年）。《生物化学杂志》262卷，8367 - 8376页]的探针分析了RNA凝胶印迹。来自幼苗和大豆悬浮培养物的信使RNA主要对应于新的RPRP克隆（1A10 - 2），而在根中稍后积累的主要信使RNA对应于SbPRP1。
