INVOLVEMENT OF GOLGI APPARATUS IN SYNTHESIS AND SECRETION OF HYDROXYPROLINE-RICH CELL-WALL GLYCOPROTEINS
INVOLVEMENT OF GOLGI APPARATUS IN SYNTHESIS AND SECRETION OF HYDROXYPROLINE-RICH CELL-WALL GLYCOPROTEINS
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DOI：
10.1104/pp.55.3.536
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发表时间：
1975-01-01
期刊：
影响因子：
7.4
通讯作者：
CHRISPEELS, MJ
中科院分区：
文献类型：
--
作者：
GARDINER, M;CHRISPEELS, MJ
胡萝卜根韧皮薄壁组织的脉冲标记。CV.南特）组织与14 C-脯氨酸，然后在蔗糖梯度上的细胞质细胞器的分级分离，用于确定参与分泌的羟脯氨酸丰富的糖蛋白的细胞壁的膜细胞器的身份。通过电子显微镜观察和标记酶在蔗糖梯度上的定位来鉴定细胞器。通过测量以14 C-羟脯氨酸形式存在的掺入放射性的百分比来确定参与分泌的细胞器的富集。高尔基体（网状体）被发现是糖蛋白运输的主要场所。这一鉴定是基于观察到的富集平行的新合成的细胞壁糖蛋白的纯化的dictyosomes。一种高尔基体的标记酶，肌苷二磷酸酶，在连续的等密度和速率带蔗糖梯度上与新合成的细胞壁糖蛋白结合。标记酶的内质网和质膜清楚地分离的富含高尔基体的馏分。UDP-阿拉伯糖阿拉伯糖基转移酶，一种参与糖蛋白的肽部分糖基化的酶，也在两种梯度上与高尔基体结合。这些结果表明，高尔基体在高等植物细胞壁糖蛋白的合成和分泌中起着重要作用。
Pulse labeling of carrot root phloem parenchyma (Daucus carotaL. cv. Nantes) tissue with14C-proline followed by fractionation of the cytoplasmic organelles on sucrose gradients was used to determine the identity of the membranous organelles involved in the secretion of the hydroxyproline-rich glycoproteins of the cell wall. Identification of the organelles was done through electron-microscopical observations and through the localization of marker enzymes on the sucrose gradients. Enrichment of the organelles involved in secretion was determined by measuring the percentage of the incorporated radioactivity present as14C-hydroxyproline. The Golgi apparatus (dictyosome) was found to be a major site of glycoprotein transport. This identification was based on the observed enrichment of dictyosomes paralleling the purification of newly synthesized cell-wall glycoproteins. A marker enzyme for the Golgi apparatus, inosinediphosphatase, banded with the newly synthesized cell wall glycoproteins on sequential isopycnic and rate zonal sucrose gradients. Marker enzymes for the endoplasmic reticulum and the plasma membrane were clearly separated from the dictyosome-rich fraction. UDP-arabinose arabinosyl transferase, an enzyme involved in the glycosylation of the peptide moiety of this glycoprotein, also banded with the dictyosomes on both kinds of gradients. The results suggest an important role of the Golgi apparatus in the biosynthesis and the secretion of the cell wall glycoproteins of higher plants.