Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
FEBS Lett. 2011 May 6;585(9):1281-6. doi: 10.1016/j.febslet.2011.04.009. Epub 2011 Apr 8.
Misfolded, luminal endoplasmic reticulum (ER) proteins must be recognized before being degraded by a process called ERAD-L. Using site-specific photocrosslinking in Saccharomyces cerevisiae, we tested luminal interactions of a glycosylated ERAD-L substrate with potential recognition components. Major interactions were observed with Hrd3p. These are independent of the glycan and of other ERAD components, and can occur throughout the length of the unfolded substrate. The lectin Yos9p only interacts with a polypeptide segment distant from the degradation signal. Hrd3p may thus be the first substrate-recognizing component. Der1p appears to have a role in a pathway that is parallel to that involving Hrd3p.
错误折叠的内质网腔（ER）蛋白必须先被识别，然后才能被一种称为 ERAD-L 的过程降解。我们在酿酒酵母中使用位点特异性光交联技术，测试了糖基化 ERAD-L 底物与潜在识别成分的腔内腔相互作用。主要的相互作用发生在 Hrd3p 上。这些相互作用不依赖于聚糖和其他 ERAD 成分，并且可以在整个未折叠底物的长度上发生。凝集素 Yos9p 仅与远离降解信号的多肽片段相互作用。因此，Hrd3p 可能是第一个识别底物的成分。Der1p 似乎在一条与涉及 Hrd3p 的途径平行的途径中发挥作用。
