Identification of a Skp1-Like Protein Interacting with SFB, the Pollen S Determinant of the Gametophytic Self-Incompatibility in Prunus
Identification of a Skp1-Like Protein Interacting with SFB, the Pollen S Determinant of the Gametophytic Self-Incompatibility in Prunus
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DOI：
10.1104/pp.112.197343
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发表时间：
2012-07-01
期刊：
影响因子：
7.4
通讯作者：
Tao, Ryutaro
中科院分区：
文献类型：
--
作者：
Matsumoto, Daiki;Yamane, Hisayo;Tao, Ryutaro
许多蔷薇科、茄科和车前草科植物表现出基于S核糖核酸酶的自交不亲和性(SI)。在这个系统中，雌蕊和花粉的专一性分别由S核糖核酸酶和S F-box蛋白决定。在蔷薇科李属中，花粉S决定F-box蛋白有两个不同的称谓，即S单倍型特异的F-box蛋白和S位点的F-box蛋白，而在茄科和车前草科植物中称为SLF。李被认为是其同源的S核糖核酸酶在不亲和反应中发挥细胞毒性和阻止花粉管生长所必需的分子。虽然最近的研究已经证明了SCFSLF在茄科和车前科SI反应中的分子功能，但SFB如何参与樱桃的SI机制仍有待阐明。本文报道了利用酵母(Saccharmyces Cerevisiae)双杂交技术对甜樱桃(Prunus Avium)SFB(PavSFB)-Skp1-like 1(PavSSK1)进行鉴定。系统发育分析表明，PavSSK1与金鱼草SLF互作Skp1-like 1和矮牵牛SLF互作Skp1-like 1(PhSSK1)属于同一分支。在酵母中，PavSSK1不仅与来自不同S单倍型的PavSFB和类Cullin1蛋白(PavCul1)相互作用，而且还与S的F-box类蛋白相互作用。下拉实验证实了PavSSK1与PavSFB以及PavSSK1与PavCul1之间的相互作用。这些结果共同表明，PavSSK1可能是SCF复合体的一个功能成分，PavSFB可能是SCF复合体的一个组成部分。我们讨论了PavSFB在李属配子体SI中自我/非自我识别中的分子功能。
Many species in Rosaceae, Solanaceae, and Plantaginaceae exhibit S-RNase-based self-incompatibility (SI). In this system, the pistil and pollen specificities are determined by S-RNase and the S locus F-box protein, respectively. The pollen S determinant F-box protein in Prunus (Rosaceae) is referred to by two different terms, SFB (for S-haplotype-specific F-box protein) and SLF (for S locus F box), whereas it is called SLF in Solanaceae and Plantaginaceae. Prunus SFB is thought to be a molecule indispensable for its cognate S-RNase to exert cytotoxicity and to arrest pollen tube growth in incompatible reactions. Although recent studies have demonstrated the molecular function of SCFSLF in the SI reaction of Solanaceae and Plantaginaceae, how SFB participates in the Prunus SI mechanism remains to be elucidated. Here we report the identification of sweet cherry (Prunus avium) SFB (PavSFB)-interacting Skp1-like1 (PavSSK1) using a yeast (Saccharomyces cerevisiae) two-hybrid screening against the pollen cDNA library. Phylogenetic analysis showed that PavSSK1 belongs to the same clade as Antirrhinum hispanicum SLF-interacting Skp1-like1 and Petunia hybrida SLF-interacting Skp1-like1 (PhSSK1). In yeast, PavSSK1 interacted not only with PavSFBs from different S haplotypes and Cullin1-likes (PavCul1s), but also with S-locus F-box-likes. A pull-down assay confirmed the interactions between PavSSK1 and PavSFB and between PavSSK1 and PavCul1s. These results collectively indicate that PavSSK1 could be a functional component of the SCF complex and that PavSFB may function as a component of the SCF complex. We discuss the molecular function of PavSFB in self-/nonself-recognition in the gametophytic SI of Prunus.