The conserved plant sterility gene HAP2 functions after attachment of fusogenic membranes in Chlamydomonas and Plasmodium gametes
The conserved plant sterility gene HAP2 functions after attachment of fusogenic membranes in Chlamydomonas and Plasmodium gametes
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DOI：
10.1101/gad.1656508
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发表时间：
2008-04-15
影响因子：
10.5
通讯作者：
Billker, Oliver
中科院分区：
文献类型：
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作者：
Liu, Yanjie;Tewari, Rita;Billker, Oliver
在雌雄配子之间的物种特异性膜融合的细胞和分子机制仍然在很大程度上未知。在这里，通过使用基因发现的方法在绿色衣原体，基因中断的啮齿类疟原虫伯氏疟原虫，受精在这两种生物体的显着特点，我们报告发现一种机制，占配子融合所需的保守蛋白质。在衣原体中筛选融合突变体鉴定了拟南芥不育基因HAP 2的同源物。此外，疟原虫中HAP2的破坏阻断了受精，从而阻断了疟疾的蚊子传播。HAP 2定位在衣原体减配子的融合位点，但衣原体减和疟原虫hap2雄配子保留的能力，使用其他，物种有限的蛋白质，形成紧密的融合前膜附件与各自的配子合作伙伴。膜染色实验表明，HAP 2是膜合并所必需的。因此，在两个远亲的真核生物中，物种限制的蛋白质控制着膜融合所必需的保守蛋白质的获取。
The cellular and molecular mechanisms that underlie species-specific membrane fusion between male and female gametes remain largely unknown. Here, by use of gene discovery methods in the green alga Chlamydomonas, gene disruption in the rodent malaria parasite Plasmodium berghei, and distinctive features of fertilization in both organisms, we report discovery of a mechanism that accounts for a conserved protein required for gamete fusion. A screen for fusion mutants in Chlamydomonas identified a homolog of HAP2, an Arabidopsis sterility gene. Moreover, HAP2 disruption in Plasmodium blocked fertilization and thereby mosquito transmission of malaria. HAP2 localizes at the fusion site of Chlamydomonas minus gametes, yet Chlamydomonas minus and Plasmodium hap2 male gametes retain the ability, using other, species-limited proteins, to form tight prefusion membrane attachments with their respective gamete partners. Membrane dye experiments show that HAP2 is essential for membrane merger. Thus, in two distantly related eukaryotes, species-limited proteins govern access to a conserved protein essential for membrane fusion.