Biochemical and structural characterization of an endoplasmic reticulum-localized late embryogenesis abundant (LEA) protein from the liverwort Marchantia polymorpha
Biochemical and structural characterization of an endoplasmic reticulum-localized late embryogenesis abundant (LEA) protein from the liverwort Marchantia polymorpha
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DOI：
10.1016/j.bbrc.2014.10.130
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发表时间：
2014-11-28
影响因子：
3.1
通讯作者：
Sugawara, Yasutake
中科院分区：
文献类型：
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作者：
Hatanaka, Rie;Furuki, Takao;Sugawara, Yasutake
晚胚发生丰富（莱亚）蛋白，在成熟后期积累到高水平的种子，与脱水耐性。莱亚蛋白家族的一员被发现在培养细胞的地钱多形;预培养处理这些细胞与0.5 M蔗糖培养基导致其收购的干燥耐受性。我们的特点是这种预培养诱导的莱亚蛋白，命名为MpLEA 1。MpLEA 1主要是亲水性的，有几个疏水残基，可能代表其推定的信号肽。该蛋白质还含有一个推定的内质网（ER）滞留序列，HEEL，在C-末端。显微镜观察表明，GFP融合的MpLEA 1主要定位于ER。重组蛋白MpLEA 1在溶液中本质上是无序的。干燥时，MpLEA 1主要从无规卷曲向α-螺旋转移。这种构象变化是组3莱亚蛋白的典型特征。重组MpLEA 1防止聚集的α-酪蛋白在干燥-再水化事件，表明MpLEA 1发挥抗聚集活性对干燥敏感的蛋白质作为一个“分子盾牌”。此外，MpLEA 1的抗聚集活性是已知防止干燥时聚集的BSA或昆虫莱亚蛋白的抗聚集活性的10倍。在这里，我们表明，ER-本地化的莱亚蛋白，MpLEA 1，具有特定的生化和结构特征组3莱亚蛋白。(C)2014爱思唯尔公司All rights reserved.
Late embryogenesis abundant (LEA) proteins, which accumulate to high levels in seeds during late maturation, are associated with desiccation tolerance. A member of the LEA protein family was found in cultured cells of the liverwort Marchantia polymorpha; preculture treatment of these cells with 0.5 M sucrose medium led to their acquisition of desiccation tolerance. We characterized this preculture-induced LEA protein, designated as MpLEA1. MpLEA1 is predominantly hydrophilic with a few hydrophobic residues that may represent its putative signal peptide. The protein also contains a putative endoplasmic reticulum (ER) retention sequence, HEEL, at the C-terminus. Microscopic observations indicated that GFP-fused MpLEA1 was mainly localized in the ER. The recombinant protein MpLEA1 is intrinsically disordered in solution. On drying, MpLEA1 shifted predominantly toward a-helices from random coils. Such changes in conformation are a typical feature of the group 3 LEA proteins. Recombinant MpLEA1 prevented the aggregation of a-casein during desiccation-rehydration events, suggesting that MpLEA1 exerts antiaggregation activity against desiccation-sensitive proteins by functioning as a "molecular shield". Moreover, the anti-aggregation activity of MpLEA1 was ten times greater than that of BSA or insect LEA proteins, which are known to prevent aggregation on drying. Here, we show that an ER-localized LEA protein, MpLEA1, possesses biochemical and structural features specific to group 3 LEA proteins. (C) 2014 Elsevier Inc. All rights reserved.