A vacuolar processing enzyme, δVPE, is involved in seed coat formation at the early stage of seed development
A vacuolar processing enzyme, δVPE, is involved in seed coat formation at the early stage of seed development
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DOI：
10.1105/tpc.104.026872
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发表时间：
2005-03-01
期刊：
影响因子：
11.6
通讯作者：
Hara-Nishimura, I
中科院分区：
文献类型：
--
作者：
Nakaune, S;Yamada, K;Hara-Nishimura, I
液泡处理酶(VPE)是一种半胱氨酸蛋白酶，负责液泡蛋白的成熟。拟南芥DeltaVPE是最近在数据库中发现的，在种子发育的早期，它在种皮的两个细胞层(ii2和ii3)特异和瞬时表达。在这个阶段，伴随着细胞收缩的细胞死亡在Ii2层发生，随后在Ii3层发生细胞死亡。在deltaVPE缺失突变体中，种皮两层的细胞死亡被延迟。免疫细胞化学分析将DeltaVPE定位于经历细胞死亡的种皮细胞壁内外的电子致密结构。有趣的是，在幼年角果的沉淀部分中，Delta VPE显示出caspase-1样活性，这在各种类型的植物细胞死亡中都被检测到。我们的结果表明，在种子发育的早期，deltaVPE参与了有限细胞层的细胞死亡，其目的是形成种皮。
Vacuolar processing enzyme (VPE) is a Cys proteinase responsible for the maturation of vacuolar proteins. Arabidopsis thaliana delta VPE, which was recently found in the database, was specifically and transiently expressed in two cell layers of the seed coat (ii2 and ii3) at an early stage of seed development. At this stage, cell death accompanying cell shrinkage occurs in the ii2 layer followed by cell death in the ii3 layer. In a delta VPE-deficient mutant, cell death of the two layers of the seed coat was delayed. Immunocytochemical analysis localized delta VPE to electron-dense structures inside and outside the walls of seed coat cells that undergo cell death. Interestingly, delta VPE in the precipitate fraction from young siliques exhibits caspase-1-like activity, which has been detected in various types of plant cell death. Our results suggest that, at the early stage of seed development, delta VPE is involved in cell death of limited cell layers, the purpose of which is to form a seed coat.