Sun Yunfang, Ning Tingting, Liu Zhenwei, Pang Jianlei, Jiang Daiming, Guo Zhibin, Song Gaoyuan, Yang Daichang
BMC Plant Biol. 2015 Feb 17;15:55. doi: 10.1186/s12870-014-0324-1.
Sec18p/N-ethylmaleimide-sensitive factor (NSF) is a conserved eukaryotic ATPase, which primarily functions in vesicle membrane fusion from yeast to human. However, the function of the OsSec18 gene, a homologue of NSF in rice, remains unknown.
In the present study, we investigated the function of OsSec18 in rice and found that OsSec18 complements the temperature-sensitive phenotype and interferes with vacuolar morphogenesis in yeast. Overexpression of OsSec18 in rice decreased the plant height and 1000-grain weight and altered the morphology of the protein bodies. Further examination revealed that OsSec18 presented as a 290-kDa complex in rice endosperm cells. Moreover, Os60sP0 was identified a component of this complex, demonstrating that the OsSec18 complex contains another complex of P0(P1-P2)2 in rice endosperm cells. Furthermore, we determined that the N-terminus of OsSec18 can interact with the N- and C-termini of Os60sP0, whereas the C-terminus of OsSec18 can only interact with the C-terminus of Os60sP0.
Our results revealed that the OsSec18 regulates vacuolar morphology in both yeast and rice endosperm cell and the OsSec18 interacts with P0(P1-P2)2 complex in rice endosperm cell.
Sec18p/N - 乙基马来酰亚胺敏感因子（NSF）是一种保守的真核ATP酶，主要在从酵母到人类的囊泡膜融合中发挥作用。然而，水稻中NSF的同源基因OsSec18的功能仍不清楚。
在本研究中，我们研究了水稻中OsSec18的功能，发现OsSec18可互补酵母的温度敏感表型并干扰酵母液泡形态发生。水稻中OsSec18的过表达降低了株高和千粒重，并改变了蛋白体的形态。进一步研究表明，OsSec18在水稻胚乳细胞中以290 kDa的复合物形式存在。此外，Os60sP0被鉴定为该复合物的一个组分，表明水稻胚乳细胞中OsSec18复合物包含另一个P0(P1 - P2)2复合物。此外，我们确定OsSec18的N端可与Os60sP0的N端和C端相互作用，而OsSec18的C端仅与Os60sP0的C端相互作用。
我们的结果表明，OsSec18在酵母和水稻胚乳细胞中均调节液泡形态，且OsSec18在水稻胚乳细胞中与P0(P1 - P2)2复合物相互作用。
