Mize N K, Andrews D W, Lingappa V R
Cell. 1986 Dec 5;47(5):711-9. doi: 10.1016/0092-8674(86)90514-3.
A stop transfer sequence derived from the extreme carboxyl terminus of membrane IgM heavy chain has been shown to confer predictable transmembrane orientation to secretory proteins by aborting translocation of subsequently synthesized protein domains. Here we demonstrate that, in certain peptide sequence contexts, the same stop transfer sequence is also capable of initiating domain translocation across the endoplasmic reticulum (ER) membrane. Translocation directed by a stop transfer sequence is similar to, but distinguishable from, the action of a conventional signal sequence. Translocation is dependent on participation of the ribosome and protein receptors both in the cytoplasm and in the ER membrane. Moreover, both amino- and carboxy-terminal flanking protein domains can be translocated. Unlike a signal sequence, the stop transfer sequence is not itself translocated across the membrane. These results have implications for the nature of signal sequences, stop transfer sequences, and their receptor interactions.
源自膜IgM重链极端羧基末端的停止转移序列已被证明，通过中止随后合成的蛋白质结构域的转运，可赋予分泌蛋白可预测的跨膜方向。在此我们证明，在某些肽序列背景下，相同的停止转移序列也能够启动结构域跨内质网（ER）膜的转运。由停止转移序列引导的转运类似于但又不同于传统信号序列的作用。转运依赖于核糖体以及细胞质和ER膜中的蛋白质受体的参与。此外，氨基末端和羧基末端侧翼的蛋白质结构域都可以被转运。与信号序列不同，停止转移序列本身不会跨膜转运。这些结果对信号序列、停止转移序列的性质及其受体相互作用具有启示意义。
