Studies on the mechanisms of autophagy: formation of the autophagic vacuole.
Studies on the mechanisms of autophagy: formation of the autophagic vacuole.
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关于自噬的机制的研究：自噬液泡的形成。
DOI：
10.1083/jcb.110.6.1923
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发表时间：
1990-06
期刊：
影响因子：
--
通讯作者：
Dunn WA Jr
中科院分区：
文献类型：
--
作者：
Dunn WA Jr
自噬空泡在向肝脏灌注氨基酸缺失培养基后15分钟内形成。这些液泡由“光滑”的双膜结合，不含酸性磷酸酶活性。为了确定这些液泡的膜源，我使用形态学技术结合免疫探针将特异性膜抗原定位到新形成或新生的自噬液泡的限制膜上。针对质膜的三种完整膜蛋白（CE9、HA4和表皮生长因子受体）和一种高尔基体（唾液基转移酶）的抗体不能标记这些液泡。内化表皮生长因子及其膜受体在新生自噬液泡中不存在，但在溶酶体样降解性自噬液泡中存在。这些结果表明，自噬液泡不是由质膜、高尔基体或核内体成分形成的。研究发现，针对内质网整体膜蛋白（14、25和40 kD）制备的抗血清可以标记几乎所有新生自噬液泡的内外限制膜。此外，在许多新生自噬液泡的限制膜上也发现了核蛋白II。最后，分泌蛋白，大鼠血清白蛋白和α 2 -球蛋白，定位于内质网的管腔和一些液泡内外膜之间的膜内空间。结果与内质网无核糖体区形成自噬液泡一致。
Autophagic vacuoles form within 15 min of perfusing a liver with amino acid-depleted medium. These vacuoles are bound by a "smooth" double membrane and do not contain acid phosphatase activity. In an attempt to identify the membrane source of these vacuoles, I have used morphological techniques combined with immunological probes to localize specific membrane antigens to the limiting membranes of newly formed or nascent autophagic vacuoles. Antibodies to three integral membrane proteins of the plasma membrane (CE9, HA4, and epidermal growth factor receptor) and one of the Golgi apparatus (sialyltransferase) did not label these vacuoles. Internalized epidermal growth factor and its membrane receptor were not found in nascent autophagic vacuoles but were present in lysosome-like degradative autophagic vacuoles. All these results suggested that autophagic vacuoles were not formed from plasma membrane, Golgi apparatus, or endosome constituents. Antisera prepared against integral membrane proteins (14, 25, and 40 kD) of the RER was found to label the inner and outer limiting membranes of almost all nascent autophagic vacuoles. In addition, ribophorin II was identified at the limiting membranes of many nascent autophagic vacuoles. Finally, secretory proteins, rat serum albumin and alpha 2u- globulin, were localized to the lumen of the RER and to the intramembrane space between the inner and outer membranes of some of these vacuoles. The results were consistent with the formation of autophagic vacuoles from ribosome-free regions of the RER.