Plant cysteine protease: multiple posttranslational processing and intracellular transport

植物半胱氨酸蛋白酶：多重翻译后加工和细胞内运输

• 批准号: 09640776
• 负责人: MINAMIKAWA Takao
• 金额: $ 1.98万
• 依托单位: TOKYO METOROPOLITAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640776/
• 关键词: cysteine protease; endopeptidase; intracellular transport; Vigna mungo; seed germination; posttranslational processing; endoplasmic reticulum; vacuole; システインプロテアーゼ; イネ; アミノ酸配列; エンドペプチダーゼ

A vacuolar cysteine proteinase, designated SH-EP, is expressed in the cotyledon of germinated Vigna mungo seeds, and is responsible for the degradation of storage proteins. SH-EP is a characteristic vacuolar proteinase possessing a carboxy-terminal endoplasmic reticulum (ER) retention secuence, KDEL. In the present work, immunocytochemical analysis of the cotyledon cells of V. mungo seeds was performed using seven kinds of antibodies to identify the intracellular transport of SH-EP from ER to protein storage vacuoles. A proform of SH-EP synthesized in ER accumulated at the edge of middle regions of ER where the transport vesicle was formed. The vesicle containing a large amount of proSH-EP, termed KV, budded off from ER, bypassed the Golgi complex and was sorted to protein storage vacuoles. This massive transport of SH-EP via KV was thought to mediate dynamic protein mobilization in the cotyledon cells of germinated seeds. We discuss the possibilities that the KDEL sequence of KDEL-tailed vacuolar cysteine proteinases functions as an accumulation signal at ER and that the mass transport of the proteinases by ER-derived KV-like vesicle is involved in the protein mobilization of plants.

液泡半胱氨酸蛋白酶SH-EP在萌发的绿豆种子的子叶中表达，负责贮藏蛋白的降解。SH-EP是一种特征性的空泡蛋白酶，具有羧基端内质网（ER）滞留活性（KDEL）。本工作用7种抗体对蒙戈葡萄种子子叶细胞进行了免疫细胞化学分析，以确定SH-EP从内质网向蛋白质贮藏泡的胞内转运。内质网合成的SH-EP前体聚集在内质网中部边缘，形成转运囊泡。含有大量proSH-EP的囊泡（称为KV）从ER出芽，绕过高尔基复合体并被分选为蛋白质储存泡。这种通过KV的SH-EP的大量运输被认为介导萌发种子的子叶细胞中的动态蛋白质动员。我们讨论的可能性，KDEL尾液泡半胱氨酸蛋白酶的KDEL序列的功能作为一个积累信号在ER和ER衍生的KV样囊泡的蛋白酶的质量运输参与植物的蛋白质动员。

项目成果

Hosokawa, T., Okamoto, T., Minamikawa, T.: "Characterization of serine endopeptidases in cotyledons of germinated Vigna mungo seeds"J. Plant Res.. 112. 217-221 (1999)

Hosokawa，T.，Okamoto，T.，Minamikawa，T.：“发芽绿豆种子子叶中丝氨酸内肽酶的表征”J。

Kato, H.and Minamikawa, T.: "Molecular cloning and possible role of an asparaginyl endopepetidase (REP-2) from germinated rice seeds." Plant Cell Physiol.印刷中. (1999)

Kato, H. 和 Minamikawa, T.：“来自发芽水稻种子的天冬酰胺酰肽内切酶 (REP-2) 的分子克隆和可能的作用”（植物细胞生理学）。

Okamoto, T., Minamikawa, T.: "A vacuolar cysteine endopeptidase (SH-EP) that digests seed storage globulin : characterization, regulation of gene expression, and posttranslational processing"J. Plant Physiol.. 152. 675-682 (1998)

Okamoto, T., Minamikawa, T.：“消化种子储存球蛋白的液泡半胱氨酸内肽酶 (SH-EP)：特征、基因表达调控和翻译后加工”J.

Okamoto, T., Minamikawa, T., Edward, G., Vakharia, V., Herman, E.: "Posttranslational removal of the carboxylterminal KDEL of the cysteine protease SH-EP occurs prior to maturation of the enzyme"J. Biol. Chem.. 274. 11390-11398 (1999)

Okamoto, T.、Minamikawa, T.、Edward, G.、Vakharia, V.、Herman, E.：“半胱氨酸蛋白酶 SH-EP 羧基末端 KDEL 的翻译后去除发生在酶成熟之前”J.

Okamoto,T., Minamikawa,T. et al: "Posttranslational removal of the carboxy1-terminal KDEL of the cysteine protease SH-EP occurs prior to maturation of the enzyme."J. Biol. Chem.. 274. 11390-11398 (1999)

冈本，T.，南川，T.