Protein–protein interactions indicate composition of a 480 kDa SELMA complex in the second outermost membrane of diatom complex plastids
Protein–protein interactions indicate composition of a 480 kDa SELMA complex in the second outermost membrane of diatom complex plastids
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DOI：
10.1111/mmi.13302
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发表时间：
2016-04
影响因子：
3.6
通讯作者：
Julia Lau;Simone Stork;D. Moog;J. Schulz;U. Maier
中科院分区：
文献类型：
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作者：
Julia Lau;Simone Stork;D. Moog;J. Schulz;U. Maier
大多数红藻起源的次生质体被四层膜包围，核编码的质体蛋白必须穿过这些屏障。跨第二个最外层质体膜，即质体周膜（PPM）的易位由ERAD-（ER-相关降解）衍生的机制（称为SELMA）促进。在过去的几年中，这个转运蛋白的重要亚基已被确定，这清楚地表明SELMA和ERAD之间的组成相似性。在这里，我们调查，通过蛋白质-蛋白质相互作用的研究，如果组成的SELMA是可比的已知ERAD复合物。因此，我们的数据表明，SELMA的膜蛋白，derlin蛋白，通过UBX蛋白sUBX连接到可溶性sCdc 48复合物。这类似于ERAD机制，而额外的SELMA组分，sPUB和第二个Cdc 48拷贝可能表明功能限制在从ERAD相关因子发展易位机制中的影响。此外，我们第一次表明，菱形蛋白酶是一个中心的相互作用伙伴的膜蛋白的SELMA系统在复杂的质体。
Most secondary plastids of red algal origin are surrounded by four membranes and nucleus‐encoded plastid proteins have to traverse these barriers. Translocation across the second outermost plastid membrane, the periplastidal membrane (PPM), is facilitated by a ERAD‐(ER‐associated degradation) derived machinery termed SELMA (symbiont‐specific ERAD‐like machinery). In the last years, important subunits of this translocator have been identified, which clearly imply compositional similarities between SELMA and ERAD. Here we investigated, via protein–protein interaction studies, if the composition of SELMA is comparable to the known ERAD complex. As a result, our data suggest that the membrane proteins of SELMA, the derlin proteins, are linked to the soluble sCdc48 complex via the UBX protein sUBX. This is similar to the ERAD machinery whereas the additional SELMA components, sPUB und a second Cdc48 copy might indicate the influence of functional constraints in developing a translocation machinery from ERAD‐related factors. In addition, we show for the first time that a rhomboid protease is a central interaction partner of the membrane proteins of the SELMA system in complex plastids.