Phospho-Chk2 (Ser516) Antibody 能够检测内源性丝氨酸(516位)磷酸化的Chk2蛋白,该抗体不与其他位点磷酸化的Chk2蛋白发生交叉反应。该多克隆抗体是由合成的人源的针对Chk2蛋白丝氨酸(516位)磷酸化的肽段免疫动物,采用蛋白A和多肽亲和层析技术纯化生产的。Chk2是哺乳动物中和芽殖酵母Rad53和裂殖酵母Cds1检验点激酶同源的蛋白(1-3)。Chk2的氨基末端结构域包含有一个七丝氨酸或者苏氨酸残基(Ser19, Thr26, Ser28, Ser33, Ser35, Ser50 and Thr68)组成的系列,每个系列紧跟着谷氨酸(SQ 或TQ模体)。这些地方是已知的ATM/ATR激酶磷酸化的首选作用位点(4,5)。电离辐射(IR)引起DNA损伤之后,UV照射处理或者羟基脲处理,这个区域的68位苏氨酸和其他位点被ATM/ATR磷酸化(5-7)。因此,SQ/TQ簇结构域似乎具有调节功能。第68位苏氨酸的磷酸化是后续激活步骤的先决条件,激活归因于激酶结构域激活回路中Chk2第383位和387位苏氨酸残基的自体磷酸化(8)。Chk2 autophosphorylation at Ser516 is important for optimal Chk2 function, and a Ser516Ala mutant Chk2 is defective in IR-induced apoptosis (9). Chk2丝氨酸(516位)自体磷酸化对于Chk2功能的最优化起到重要作用,丝氨酸(516位)丙氨酸突变的Chk2在辐射诱导的凋亡中发生功能缺陷。
Phospho-Chk2 (Ser516) Antibody detects endogenous levels of Chk2 only when phosphorylated at serine 516. The antibody does not cross-react with Chk2 phosphorylated at other sites.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser516 of human Chk2. Antibodies are purified by protein A and peptide affinity chromatography.
Background
Chk2 is the mammalian orthologue of the budding yeast Rad53 and fission yeast Cds1 checkpoint kinases (1-3). The amino-terminal domain of Chk2 contains a series of seven serine or threonine residues (Ser19, Thr26, Ser28, Ser33, Ser35, Ser50 and Thr68) each followed by glutamine (SQ or TQ motif). These are known to be preferred sites for phosphorylation by ATM/ATR kinases (4,5). After DNA damage by ionizing radiation (IR), UV irradiation or hydroxyurea treatment, Thr68 and other sites in this region become phosphorylated by ATM/ATR (5-7). The SQ/TQ cluster domain, therefore, seems to have a regulatory function. Phosphorylation at Thr68 is a prerequisite for the subsequent activation step, which is attributable to autophosphorylation of Chk2 on residues Thr383 and Thr387 in the activation loop of the kinase domain (8)