Lewis M J, Sweet D J, Pelham H R
MRC Laboratory of Molecular Biology, Cambridge, England.
Cell. 1990 Jun 29;61(7):1359-63. doi: 10.1016/0092-8674(90)90699-f.
Luminal ER proteins carry a signal at their C terminus that prevents their secretion; in S. cerevisiae this signal is the tetrapeptide HDEL. Indirect evidence suggests that HDEL is recognized by a receptor that retrieves ER proteins from the secretory pathway and returns them to the ER, and a candidate for this receptor is the product of the ERD2 gene (see accompanying paper). We show here that presumptive ER proteins from the budding yeast K. lactis can terminate either with HDEL or, in the case of BiP, with DDEL. S. cerevisiae does not efficiently recognize DDEL as a retention signal, but exchange of its ERD2 gene for the corresponding gene from K. lactis allows equal recognition of DDEL and HDEL. Thus the specificity of the retention system is determined by the ERD2 gene. We conclude that ERD2 encodes the receptor that sorts luminal ER proteins.
内质网腔ER蛋白在其C末端携带一个阻止其分泌的信号；在酿酒酵母中，这个信号是四肽HDEL。间接证据表明，HDEL被一种受体识别，该受体从分泌途径中回收ER蛋白并将它们返回内质网，这种受体的一个候选者是ERD2基因的产物（见随附论文）。我们在此表明，来自出芽酵母乳酸克鲁维酵母的假定ER蛋白可以以HDEL结尾，或者就BiP而言，以DDEL结尾。酿酒酵母不能有效地将DDEL识别为保留信号，但是将其ERD2基因换成乳酸克鲁维酵母的相应基因后，就能同等程度地识别DDEL和HDEL。因此，保留系统的特异性由ERD2基因决定。我们得出结论，ERD2编码对内质网腔ER蛋白进行分类的受体。
