New microsome-associated HT-family proteins from Nicotiana respond to pollination and define an HT/NOD-24 protein family
New microsome-associated HT-family proteins from Nicotiana respond to pollination and define an HT/NOD-24 protein family
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DOI：
10.1093/mp/ssn018
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发表时间：
2008-07-01
期刊：
影响因子：
27.5
通讯作者：
McClure, Bruce
中科院分区：
文献类型：
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作者：
Kondo, Katsuhiko;McClure, Bruce
HT家族蛋白已在烟草、茄属和矮牵牛中鉴定。HT-B型蛋白质与基于S-RNase的自交不亲和性有关，但其他家族成员的功能尚不清楚。在烟草（Nicotiana阿拉塔）中筛选与HT-B表达模式相似的cDNA序列，发现了一组新的小HT家族蛋白，命名为HT-M。HT-M蛋白在几个方面类似于HT-B：它们的雌蕊特异性表达模式与HT-B没有区别，它们与微粒体部分一起沉淀，并且它们的丰度在授粉后降低。与HT-B不同，这种反应没有S特异性，RNAi实验表明HT-M蛋白不是自交不亲和所必需的。鉴定第三组雌蕊特异性HT家族蛋白有助于更好地定义该家族的特征，并允许鉴定推定的新家族成员。通过搜索数据库，只有最保守的HT家族序列元素，信号序列和半胱氨酸基序，我们确定了类胰高血糖素-24蛋白和几个小的富含甘氨酸的蛋白质作为推定的HT家族成员。与HT-M和HT-B一样，白藜芦醇-24也是膜结合的。我们认为HT家族蛋白中的保守特征对于靶向或修饰是重要的，并将包括HT和类胰蛋白酶24蛋白的更广泛的家族称为HT/NOD-24家族。
HT-family proteins have been identified in Nicotiana, Solanum, and Petunia. HT-B-type proteins are implicated in S-RNase-based self-incompatibility, but the functions of other family members are unknown. Screening for cDNA sequences with an expression pattern similar to HT-B in Nicotiana alata revealed a new group of small HT-family proteins, designated HT-M. HT-M proteins resemble HT-B in several respects: their pistil-specific expression pattern is indistinguishable from HT-B, they pellet with a microsome fraction, and their abundance decreases after pollination. Unlike HT-B, there is no S-specificity to this response, and RNAi experiments show that HT-M proteins are not necessary for self-incompatibility. Identification of a third group of pistil-specific HT-family proteins helps better define the characteristics of the family and allowed identification of putative new family members. By searching the databases with only the most conserved HT-family sequence elements, the signal sequence and cysteine motifs, we identified nodulin-24-like proteins and several small glycine-rich proteins as putative HT-family members. Like HT-M and HT-B, nodulin-24 is membrane associated. We propose that the conserved features in HT-family proteins are important for targeting or modification and refer to the broader family that includes both HT-and nodulin-24-like proteins as the HT/NOD-24-family.