The BC box CRISPR screens identified the FEM family adaptors as critical for the degradation of the peptides ending in arginine, with Cul2FEM1B responsible for the degradation of the GFP-CDK5R1 peptide fusion and both Cul2FEM1A and Cul2FEM1C required for the degradation of the GFP-SIL1 peptide fusion .
BC盒CRISPAR筛查发现FEM家族的蛋白接头对末端为精氨酸的多肽的降解至关重要。其中Cul2FEM1B负责GFP-CKD5R1肽的降解，Cul2FEM1A和Cul2FEM1C是GFP-SIL1融合肽的降解所必须的。
As expected, Cul2 and Elongin C scored in both clones. The identification of the FEM family adaptors was intriguing, as previously we found that several of the unstable GFP-peptides from the original GPS-peptidome library (Clones 9-17) were stabilized by knockout of either FEM1A/FEM1C or FEM1B .
和预期一致，Cul2H和ElonginC在两个组中都被证实了。FEM家族蛋白接头的鉴定是有意义的，因为我们之前发现，不稳定的GFP多肽因为FEM1A或FEM1或FEM1B的敲除而变得稳定。
With the exception of clone 17,all of these constructs terminated with –QGRAR*, a common sequence derived from the backbone of the GPS expression vector. These findings supports the hypothesis that Cul2FEM1A-C complexes target substrates ending in arginine (Figure 6G).
除了克隆17外，所有的构建物都以QGRAR终止，这是常见的GPS表达载体衍生序列。这些发现支持了Cul2FEM1A-C复合物以精氨酸末端的底物为靶标
However, given that all (with the exception of peptides derived from the C-terminus of proteins) of the full-length GFP-peptide fusion proteins in the GPS-peptidome library terminate with –QGRAR*,and yet only a small proportion of these proteins are substrates for Cul2FEM1A-C, we anticipate that the full degron recognized by FEM adaptors must be considerably more complex.
然而，由于GPS-多肽文库中所有的全长GFP-多肽融合蛋白(来自蛋白质C末端的多肽)都以-QGRAR*结尾，而这些蛋白中只有一小部分是Cul2FEM1A-C的底物，我们预测由FEM适配子识别的完整降解一定要复杂得多。
