Baxley Ryan M, Bullard James D, Klein Michael W, Fell Ashley G, Morales-Rosado Joel A, Duan Tingting, Geyer Pamela K
Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, IA 52242, USA.
Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.
Nucleic Acids Res. 2017 May 5;45(8):4463-4478. doi: 10.1093/nar/gkx040.
Polydactyl zinc finger (ZF) proteins have prominent roles in gene regulation and often execute multiple regulatory functions. To understand how these proteins perform varied regulation, we studiedDrosophila Suppressor of Hairy-wing [Su(Hw)], an exemplar multifunctional polydactyl ZF protein. We identified separation-of-function (SOF) alleles that encode proteins disrupted in a single ZF that retain one of the Su(Hw) regulatory activities. Through extended in vitro analyses of the Su(Hw) ZF domain, we show that clusters of ZFs bind individual modules within a compound DNA consensus sequence. Through in vivo analysis of SOF mutants, we find that Su(Hw) genomic sites separate into sequence subclasses comprised of combinations of modules, with subclasses enriched for different chromatin features. These data suggest a Su(Hw) code, wherein DNA binding dictates its cofactor recruitment and regulatory output. We propose that similar DNA codes might be used to confer multiple regulatory functions of other polydactyl ZF proteins.
多锌指（ZF）蛋白在基因调控中发挥着重要作用，并且常常执行多种调控功能。为了了解这些蛋白如何进行多样化调控，我们研究了果蝇毛翅抑制因子[Su(Hw)]，这是一种典型的多功能多锌指蛋白。我们鉴定出了功能分离（SOF）等位基因，这些等位基因编码的蛋白在单个锌指中被破坏，但保留了Su(Hw)的一种调控活性。通过对Su(Hw)锌指结构域进行扩展的体外分析，我们发现锌指簇结合复合DNA共有序列内的各个模块。通过对SOF突变体进行体内分析，我们发现Su(Hw)基因组位点可分为由模块组合构成的序列亚类，不同亚类富含不同的染色质特征。这些数据提示了一种Su(Hw)编码方式，其中DNA结合决定了其辅因子募集和调控输出。我们提出，类似的DNA编码方式可能用于赋予其他多锌指蛋白多种调控功能。
