UBIQUITIN PROTEIN CONJUGATES ACCUMULATE IN THE LYSOSOMAL SYSTEM OF FIBROBLASTS TREATED WITH CYSTEINE PROTEINASE-INHIBITORS
UBIQUITIN PROTEIN CONJUGATES ACCUMULATE IN THE LYSOSOMAL SYSTEM OF FIBROBLASTS TREATED WITH CYSTEINE PROTEINASE-INHIBITORS
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DOI：
10.1042/bj2630047
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发表时间：
1989-10-01
影响因子：
4.1
通讯作者：
MAYER, RJ
中科院分区：
文献类型：
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作者：
DOHERTY, FJ;OSBORN, NU;MAYER, RJ
小鼠成纤维细胞(3T3-L1细胞)在溶酶体半胱氨酸组织蛋白抑制剂(包括E-)存在下孵育时，积累与泛素结合的洗涤剂和盐不溶的蛋白质聚集体。这些泛素-蛋白结合物在密度梯度上与溶酶体共分，在电子显微镜下发现于多个囊泡致密小体中，似乎参与了微自噬。E-和氯化铵均能增加细胞内游离泛素的浓度，但只有E-才能导致溶酶体泛素-蛋白质结合物的形成。这一结果与泛素结合在细胞内的可能作用有关。
Mouse fibroblasts (3T3-L1 cells) accumulate detergent- and salt-insoluble aggregates of proteins conjugated to ubiquitin when incubated in the presence of inhibitors of lysosomal cysteine cathepsins, including E-64. These ubiquitin-protein conjugates co-fractionate with lysosomes on density gradients and are found in multivesicular dense bodies which by electron microscopy appear to be engaged in microautophagy. Both E-64 and ammonium chloride increase the intracellular concentration of free ubiquitin, but only E-64 leads to the formation of insoluble lysosomal ubiquitin-protein conjugates. The results are discussed in relation to the possible intracellular roles of ubiquitin conjugation.