Powdery mildew fungal effector candidates share N-terminal Y/F/WxC-motif
Powdery mildew fungal effector candidates share N-terminal Y/F/WxC-motif
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DOI：
10.1186/1471-2164-11-317
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发表时间：
2010-05-20
期刊：
影响因子：
4.4
通讯作者：
Thordal-Christensen, Hans
中科院分区：
文献类型：
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作者：
Godfrey, Dale;Bohlenius, Henrik;Thordal-Christensen, Hans
背景：白粉病和锈病真菌是广泛存在的严重病原体，依赖于植物细胞中发育的吸器。吸器通过植物细胞衍生的吸器外膜与宿主细胞质分离。它们分泌效应蛋白，其中一些随后通过这层膜转移到植物细胞以抑制防御。结果：在含有白粉病吸器的大麦表皮cDNA文库中，三分之二的est序列为真菌，代表了3000个相似的基因。许多高度表达的基因编码带有n端信号肽的小蛋白。虽然这些蛋白是新的且相关性较差，但它们在成熟蛋白的n端共享一个三个氨基酸基序，我们将其命名为“Y/F/WxC”。这个基序的第一个氨基酸是芳香的：酪氨酸、苯丙氨酸或色氨酸，最后一个总是半胱氨酸。我们总共鉴定了107个这样的蛋白质，其中ESTs代表了我们文库中19%的真菌克隆，这表明它们在吸器功能中起着重要作用。虽然白粉病Y/F/ wxc蛋白之间的总体序列相似性较低，但它们确实具有高度相似的外显子-内含子结构，表明它们具有共同的起源。有趣的是，对公共真菌基因组和EST数据库的搜索显示，产吸器的锈菌也编码大量具有信号肽和Y/F/ wxc基序的新型短蛋白。从不产生吸器的真菌或产生吸器的卵菌的基因组和EST序列中均未发现大量此类蛋白质。结论：从大麦白粉病、小麦茎锈病和小麦叶锈病真菌中分别鉴定出107个、178个和57个Y/F/ wxc蛋白。综上所述，我们的研究结果表明，Y/F/ wxc蛋白是产吸器病原真菌的一类新的效应蛋白。
Background: Powdery mildew and rust fungi are widespread, serious pathogens that depend on developing haustoria in the living plant cells. Haustoria are separated from the host cytoplasm by a plant cell-derived extrahaustorial membrane. They secrete effector proteins, some of which are subsequently transferred across this membrane to the plant cell to suppress defense.Results: In a cDNA library from barley epidermis containing powdery mildew haustoria, two-thirds of the sequenced ESTs were fungal and represented similar to 3,000 genes. Many of the most highly expressed genes encoded small proteins with N-terminal signal peptides. While these proteins are novel and poorly related, they do share a three-amino acid motif, which we named "Y/F/WxC", in the N-terminal of the mature proteins. The first amino acid of this motif is aromatic: tyrosine, phenylalanine or tryptophan, and the last is always cysteine. In total, we identified 107 such proteins, for which the ESTs represent 19% of the fungal clones in our library, suggesting fundamental roles in haustoria function. While overall sequence similarity between the powdery mildew Y/F/WxC-proteins is low, they do have a highly similar exon-intron structure, suggesting they have a common origin. Interestingly, searches of public fungal genome and EST databases revealed that haustoria-producing rust fungi also encode large numbers of novel, short proteins with signal peptides and the Y/F/WxC-motif. No significant numbers of such proteins were identified from genome and EST sequences from either fungi which do not produce haustoria or from haustoria-producing Oomycetes.Conclusion: In total, we identified 107, 178 and 57 such Y/F/WxC-proteins from the barley powdery mildew, the wheat stem rust and the wheat leaf rust fungi, respectively. All together, our findings suggest the Y/F/WxC-proteins to be a new class of effectors from haustoria-producing pathogenic fungi.