The transferrin receptor and the tetraspanin web molecules CD9, CD81, and CD9P-1 are differentially sorted into exosomes after TPA treatment of K562 cells
The transferrin receptor and the tetraspanin web molecules CD9, CD81, and CD9P-1 are differentially sorted into exosomes after TPA treatment of K562 cells
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DOI：
10.1002/jcb.21318
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发表时间：
2007-10-15
影响因子：
4
通讯作者：
Rubinstein, Eric
中科院分区：
文献类型：
--
作者：
Abache, Toufik;Le Naour, Francois;Rubinstein, Eric
在这里，我们表明，治疗K562细胞与佛波醇酯TPA诱导下调各种表面抗原。其中，转铁蛋白受体（TfR）、四跨膜蛋白CD 81和CD 81相关蛋白CD 9 P-1的表达水平在孵育24 h后低于3 h后。我们证明，像TfR一样，CD 81在早期被内化，在后期合成较少。尽管与CD 81的一部分的TfR的协会，这两个分子进行不同的命运。TPA增加了CD 81和CD 9 P-1向外来体的靶向，但强烈降低了TfR在这些囊泡中的定位。使用该模型，我们已经表明，外泌体中的一部分CD 81和CD 9 P-1来自表面池，并且这些分子在外泌体中保持缔合。然而，在不存在CD 81和另一种四跨膜蛋白CD 9的情况下，CD 9 P-1可以靶向外泌体。将CD 9靶向到外来体中不需要蛋白质的棕榈酰化。
Here we show that treatment of K562 cells with the phorbol ester TPA induces the down-modulation of various surface antigens. Among them, the transferrin receptor (TfR), the tetraspanin CD81, and a CD81-associated protein, CD9P-1, were unique in that their expression levels were lower after 24 h incubation than after 3 h. We demonstrated that like the TfR, CD81 was internalized at early times, and was less synthesized at latter times. Despite the association of a fraction of the TfR with CD81, these two molecules were subjected to different fates. TPA increased targeting of CD81 and CD9P-1 into exosomes but strongly reduced the localization of the TfR in these vesicles. Using this model we have shown that a fraction of CD81 and CD9P-1 in exosomes comes from a surface pool and that these molecules remain associated in exosomes. However, CD9P-1 could be targeted to exosomes in the absence of CD81 and of another tetraspanin, CD9. The targeting of CD9 into exosomes did not require palmitoylation of the protein.