The pipsqueak protein of Drosophila melanogaster binds to GAGA sequences through a novel DNA-binding domain
The pipsqueak protein of Drosophila melanogaster binds to GAGA sequences through a novel DNA-binding domain
复制标题
DOI：
10.1074/jbc.273.43.28504
复制
发表时间：
1998-10-23
影响因子：
4.8
通讯作者：
Korge, G
中科院分区：
文献类型：
--
作者：
Lehmann, M;Siegmund, T;Korge, G
Pipsqueak (Psq) 属于由系统发育上古老的蛋白质-蛋白质相互作用基序定义的蛋白质家族，与 GAGA 因子和该家族的其他成员一样，Psq 是果蝇中重要的发育调节因子，在卵子发生、胚胎模式形成和成体发育过程中具有多效性功能。 GAGA 因子通过与含有 GAGAG 共有基序的控制元件结合来控制同源基因和其他基因的转录激活。结合与开放染色质结构的形成相关，该结构使转录激活剂可接近控制区域。我们在此表明，Psq 包含一个新的 DNA 结合结构域，它与 GAGA 因子锌指 DNA 结合结构域一样，结合到包含 GAGAG 共有基序的靶位点。与 GAGA 因子和该家族的其他蛋白一样，结合被相关的蛋白质-蛋白质相互作用基序抑制。DNA 结合结构域（我们称为 Psq 结构域）与之前的 DNA 结合结构域相同。鉴定出由保守的 50 个氨基酸序列的四个串联重复组成的区域，Psq 基序，Psq 结构域似乎在结构上与已知的 DNA 结合结构域相关，无论是在其重复特征还是在 Psq 基序的推定三α螺旋结构中，但它缺乏经典真核 DNA 结合基序的保守序列特征，因此 Psq 可能代表新的 DNA 结合蛋白家族的原型。
Pipsqueak (Psq) belongs to a family of proteins defined by a phylogenetically old protein-protein interaction motif, Like the GAGA factor and other members of this family, Psq is an important developmental regulator in Drosophila, having pleiotropic functions during oogenesis, embryonic pattern formation, and adult development. The GAGA factor controls the transcriptional activation of homeotic genes and other genes by binding to control elements containing the GAGAG consensus motif. Binding is associated with formation of an open chromatin structure that makes the control regions accessible to transcriptional activators, We show here that Psq contains a novel DNA-binding domain, which binds, like the GAGA factor zinc finger DNA-binding domain, to target sites containing the GAGAG consensus motif, Binding is suppressed, as in the GAGA factor and other proteins of the family, by the associated protein-protein interaction motif, The DNA-binding domain, which we call the Psq domain, is identical with a previously identified region consisting of four tandem repeats of a conserved 50-amino acid sequence, the Psq motif, The Psq domain seems to be structurally related to known DNA-binding domains, both in its repetitive character and in the putative three-alpha-helix structure of the Psq motif, but it lacks the conserved sequence signatures of the classical eukaryotic DNA-binding motifs, Psq may thus represent the prototype of a new family of DNA-binding proteins.