Wu Shumin, Trievel Raymond C, Rice Judd C
University of Southern California Keck School of Medicine, Department of Biochemistry and Molecular Biology, Los Angeles, CA 90033, USA.
FEBS Lett. 2007 Jul 10;581(17):3289-96. doi: 10.1016/j.febslet.2007.06.025. Epub 2007 Jun 21.
Human SFMBT (hSFMBT) is postulated to be a Polycomb (PcG) protein. Similar to other PcG proteins, we found that hSFMBT displays robust transcriptional repressor activity. In addition, hSFMBT localized to the nucleus where it strongly associates with chromatin by directly and selectively binding the N-terminal tail of histone H3. Importantly, we discovered that the four tandem MBT repeats of hSFMBT were sufficient for nuclear matrix-association, N-terminal tail H3 binding, and required for transcriptional repression. These findings indicate that the tandem MBT repeats form a functional structure required for biological activity of hSFMBT and predict similar properties for other MBT domain-containing proteins.
据推测，人类Sfmbt（hSFMBT）是一种多梳（PcG）蛋白。与其他PcG蛋白类似，我们发现hSFMBT具有强大的转录抑制活性。此外，hSFMBT定位于细胞核，通过直接和选择性地结合组蛋白H3的N端尾部与染色质紧密结合。重要的是，我们发现hSFMBT的四个串联MBT重复序列足以实现核基质结合、N端尾部H3结合，并且是转录抑制所必需的。这些发现表明，串联MBT重复序列形成了hSFMBT生物学活性所需的功能结构，并预测其他含MBT结构域的蛋白具有类似特性。
