Department of Cell Biology, Institute of Biomembranes, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands.
Cell Signal. 2011 Apr;23(4):641-7. doi: 10.1016/j.cellsig.2010.11.015. Epub 2010 Dec 5.
SCF(βTrCP) is the ubiquitin ligase for a wide variety of substrates and functions in many cellular processes. βTrCP, the substrate binding factor of the SCF complex, has two isoforms, produced from different genes, and several splice variants. Despite a certain level of redundancy, knock-out studies show different phenotypes indicating different preferential substrates for the two isoforms. However, until now functional differences between βTrCP1 and 2 were not studied at the endogenous protein level. We generated isoform-specific antibodies against βTrCP to characterise endogenous βTrCP isoforms and splice variants. We show that endogenous βTrCP1 and 2 localise to both nucleus and cytosol. Interestingly, we find that one splice variant of βTrCP2 localises exclusively to the nucleus and another only to the cytosol. In addition, we show that the substrate binding domain of βTrCP is the dominant localisation determinant.
SCF（βTrCP）是多种底物的泛素连接酶，在许多细胞过程中发挥作用。βTrCP 是 SCF 复合物的底物结合因子，有两种异构体，由不同的基因产生，并有几种剪接变体。尽管存在一定程度的冗余，但敲除研究表明不同的表型表明两种异构体有不同的优先底物。然而，到目前为止，还没有在内源性蛋白水平上研究βTrCP1 和 2 之间的功能差异。我们针对βTrCP 生成了同工型特异性抗体，以表征内源性βTrCP 同工型和剪接变体。我们表明内源性βTrCP1 和 2 定位于细胞核和细胞质。有趣的是，我们发现βTrCP2 的一种剪接变体仅定位于细胞核，另一种仅定位于细胞质。此外，我们表明βTrCP 的底物结合结构域是主要的定位决定因素。
