CHARACTERIZATION OF A GENE FAMILY ABUNDANTLY EXPRESSED IN OENOTHERA-ORGANENSIS POLLEN THAT SHOWS SEQUENCE SIMILARITY TO POLYGALACTURONASE
CHARACTERIZATION OF A GENE FAMILY ABUNDANTLY EXPRESSED IN OENOTHERA-ORGANENSIS POLLEN THAT SHOWS SEQUENCE SIMILARITY TO POLYGALACTURONASE
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DOI：
10.1105/tpc.2.3.263
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发表时间：
1990-03-01
期刊：
影响因子：
11.6
通讯作者：
CROUCH, ML
中科院分区：
文献类型：
--
作者：
BROWN, SM;CROUCH, ML
我们分离并表征了月见草花粉中表达的基因家族 (P2) 的 cDNA 克隆。该家族包含大约六到八个家庭成员，并且仅在花粉中高水平表达。来自近全长 cDNA 克隆的预测蛋白质序列表明，这些基因的蛋白质产物至少为 38,000 道尔顿。我们通过使用针对β-半乳糖苷酶/花粉cDNA融合蛋白的抗体鉴定了由该家族中的cDNA之一编码的蛋白质。使用这些抗体进行的免疫印迹分析鉴定了成熟花粉中存在的大约 40 千道尔顿的蛋白质家族，表明这些 mRNA 不仅仅被储存用于花粉萌发后的翻译。这些蛋白质在花粉发育后期积累，并且在植物的其他部分中检测不到。尽管在未授粉或自花授粉花柱中不存在，但在异花授粉花柱的提取物中可检测到 40 千道尔顿至 45 千道尔顿抗原，这表明这些蛋白质存在于授粉期间通过花柱生长的花粉管中。这些蛋白质也存在于体外生长的花粉管中。核苷酸和氨基酸序列均与已发表的编码多聚乳糖醛酸酶的 cDNA 序列相似，这表明 P2 基因家族可能在花粉发育、发芽和管生长过程中发挥果胶解聚作用。在多种植物的花粉中检测到交叉杂交的RNA和免疫反应蛋白，这表明多聚半乳糖醛酸酶样基因的P2家族是保守的，并且可能在许多被子植物的花粉中表达。
We have isolated and characterized cDNA clones of a gene family (P2) expressed in Oenothera organensis pollen. This family contains approximately six to eight family members and is expressed at high levels only in pollen. The predicted protein sequence from a near full-length cDNA clone shows that the protein products of these genes are at least 38,000 daltons. We identified the protein encoded by one of the cDNAs in this family by using antibodies to .beta.-galactosidase/pollen cDNA fusion proteins. Immunoblot analysis using these antibodies identifies a family of proteins of approximately 40 kilodaltons that is present in mature pollen, indicating that these mRNAs are not stored solely for translation after pollen germination. These proteins accumulate late in pollen development and are not detectable in other parts of the plant. Although not present in unpollinated or self-pollinated styles, the 40-kilodalton to 45-kilodalton antigens are detectable in extracts from cross-pollinated styles, suggesting that the proteins are present in pollen tubes growing through the style during pollination. The proteins are also present in pollen tubes growing in vitro. Both nucleotide and amino acid sequences are similar to the published sequences for cDNAs encoding the enzyme polyglacturonase, which suggests that the P2 gene family may function in depolymerizing pectin during pollen development, germination, and tube growth. Cross-hybridizing RNAs and immunoreactive proteins were detected in pollen from a wide variety of plant species, which indicates that the P2 family of polygalacturonase-like genes are conserved and may be expressed in the pollen from many angiosperms.