Urban Jennifer A, Urban John M, Kuzu Guray, Larschan Erica N
Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, RI, United States of America.
PLoS One. 2017 Dec 27;12(12):e0189772. doi: 10.1371/journal.pone.0189772. eCollection 2017.
Gaining new insights into gene regulation involves an in-depth understanding of protein-protein interactions on chromatin. A powerful model for studying mechanisms of gene regulation is dosage compensation, a process that targets the X-chromosome to equalize gene expression between XY males and XX females. We previously identified a zinc finger protein in Drosophila melanogaster that plays a sex-specific role in targeting the Male-specific lethal (MSL) dosage compensation complex to the male X-chromosome, called the Chromatin-Linked Adapter for MSL Proteins (CLAMP). More recently, we established that CLAMP has non-sex-specific roles as an essential protein that regulates chromatin accessibility at promoters genome-wide. To identify associations between CLAMP and other factors in both male and female cells, we used two complementary mass spectrometry approaches. We demonstrate that CLAMP associates with the transcriptional regulator complex Negative Elongation Factor (NELF) in both sexes and determine that CLAMP reduces NELF recruitment to several target genes. In sum, we have identified many new CLAMP-associated factors and provide a resource for further study of this little understood essential protein.
深入了解基因调控需要深入理解染色质上的蛋白质-蛋白质相互作用。研究基因调控机制的一个强大模型是剂量补偿，这是一个针对X染色体以平衡XY雄性和XX雌性之间基因表达的过程。我们之前在黑腹果蝇中鉴定出一种锌指蛋白，它在将雄性特异性致死（MSL）剂量补偿复合体靶向雄性X染色体方面发挥性别特异性作用，称为MSL蛋白的染色质连接衔接子（CLAMP）。最近，我们证实CLAMP具有非性别特异性作用，作为一种必需蛋白在全基因组范围内调节启动子处的染色质可及性。为了鉴定CLAMP与雄性和雌性细胞中其他因子之间的关联，我们使用了两种互补的质谱方法。我们证明CLAMP在两性中都与转录调节复合体负延伸因子（NELF）相关联，并确定CLAMP减少了NELF对几个靶基因的募集。总之，我们鉴定出了许多新的与CLAMP相关的因子，并为进一步研究这种了解甚少的必需蛋白提供了资源。
