糖脂 MPIase 是 TAT（双精氨酸转运）通路所必需的
Glycolipid MPIase is essential for the TAT (twin-arginine translocation) pathway
糖脂 MPIase 被证明是 TAT 转运系统必需组分：在重组 Escherichia coli 中过表达 TatABC 会提高 MPIase 水平，而耗竭 MPIase 导致 TAT 前体蛋白在胞质中积累。将 MPIase 与 TatABC 共同重构后，TAT 底物表现出依赖质子动势的转运活性，这是 TAT 系统首次成功重构，有助于理解其机制。
来源：eLife · doi.org
TAT (twin-arginine translocation) is a preprotein translocation system dedicated to membrane translocation of prefolded proteins in plants and bacteria. The TAT translocon, consisting of the TatABC subunits, drives translocation using proton motive force. However, there have been no reports on the successful reconstitution of the TAT system. In this report, we show that MPIase, a glycolipid that has been known to catalyze membrane protein integration, is essential for the TAT system. Our findings in recombinant Escherichia coli demonstrate that overproducing TatABC increases MPIase levels, and that depleting MPIase results in TAT precursor accumulation in the cytosol. Furthermore, co-reconstitution of MPIase with TatABC revealed the translocation activities of TAT substrates in a proton motive force-dependent manner. This is the first successful reconstitution of the TAT system and will be advantageous for understanding its mechanisms.