Autophagosome-associated variant isoforms of cytosolic enzymes
Autophagosome-associated variant isoforms of cytosolic enzymes
复制标题
DOI：
10.1042/0264-6021:3520773
复制
发表时间：
2000-12-15
影响因子：
4.1
通讯作者：
Seglen, PO
中科院分区：
文献类型：
--
作者：
Fengsrud, M;Raiborg, C;Seglen, PO
寻找自噬体相关蛋白。从纯化的自噬体、核后上清液中对蛋白质进行二维凝胶分离。比较了细胞质、溶酶体、线粒体、内体和细胞膜部分（主要是内质网）。三种蛋白质的单体分子量分别为 43、35 和 31 kDa，相对于核后上清液的相应部分，在自噬体的总部分或可沉积部分中富集，表明与自噬体分隔膜相关。这些蛋白质也存在于溶酶体膜上，但线粒体中不存在，并且仅在细胞膜部分和内体中检测到少量，表明它们与自噬隔离的细胞器无关。然而，所有三种蛋白质都存在于胞质溶胶中，表明它们是与自噬体的界定膜外围结合的胞质蛋白，可能与其最内表面结合，如它们对用蛋白酶或蛋白质剥离剂处理完整自噬体的抵抗力所表明的。氨基酸测序鉴定出这些蛋白质是精氨琥珀酸合酶的同种型、3-磷酸甘油醛脱氢酶的 N-截短变体和短链 2-烯酰基-CoA 水合酶的序列变体。
In a search for autophagssome-associated proteins. two-dimensional gel separations of proteins from purified autophagosomes, postnuclear supernatant. cytosol, lysosomes, mitochondria, endosomes and a cytomembrane fraction (mostly endoplasmic reticulum) were compared. Three proteins, with monomeric molecular masses of 43, 35 and 31 kDa, were enriched in total or sedimentable fractions of autophagosomes relative to the corresponding fractions of postnuclear supernatant, suggesting an association with the autophagosomal delimiting membrane. These proteins were also present on lysosomal membranes, but they were absent from mitochondria, and detected only in small amounts in the cytomembrane fraction and in endosomes, indicating that they were not associated with organelles sequestered by autophagy. However, all three proteins were present in the cytosol, suggesting that they were cytosolic proteins binding peripherally to the delimiting membrane of autophagosomes, probably to its innermost surface as indicated by their resistance to treatment of intact autophagosomes with proteinase or protein-stripping agents. Amino acid sequencing identified these proteins as an isoform of argininosuccinate synthase, an N-truncated variant of glyceraldehyde-3-phosphate dehydrogenase, and a sequence variant of short-chain 2-enoyl-CoA hydratase.