Claspin Antibody

• 产品编号：CST-2800S      品牌：CST       原厂货号：2800S
• 产品分类：抗体 > 一抗 > 蛋白特异性一抗
• 应用分类：

描述：

 Claspin Antibody能够检测内源性claspin总蛋白。该多克隆抗体是由合成的人源的针对claspin蛋白羧基末端的肽段免疫动物，使用多肽亲和层析技术纯化生产的。 Claspin最初在爪蟾中被鉴定，后来在人类中也被鉴定，它是复制检验点中Chk1信号转导通路的中介体并响应DNA损伤。Claspin的表达受细胞周期的影响，S/G2期蛋白水平达峰值(2)。蛋白酶体和caspase介导的降解都可以负调控claspin的表达(3)，其稳定需要Chk1的激活(4)。Claspin是一种染色质结合蛋白，在没有DNA损伤出现时，它可以与PNCA复合体相互作用(5)。伴随检验点的激活，它依然与染色质结合但是从PNCA复合体中释放出来，并以ATR-依赖的方式进行磷酸化。磷酸化的claspin能够与DNA损伤应激的几个成分如BRCA1 (6)和 Chk1 (7)相互作用，导致每个蛋白发生ATR-依赖的磷酸化。Rad17的磷酸化也被发现可以结合并调控claspin的磷酸化(8)。有人认为claspin在某些情况下能发挥肿瘤抑制基因的作用，因为其下调可以促进基因毒性应激反应带来的凋亡(2)。相反的，claspin在其它的情况下是致癌基因，因为其过表达能促进细胞增殖(6)。有研究建议上调的claspin可以作为异常增殖细胞的敏感标志物(9)。

1. Kumagai, A. and Dunphy, W.G. (2000) Mol Cell 6, 839-49.
2. Chini, C.C. and Chen, J. (2003) J Biol Chem 278, 30057-62.
3. Semple, J.I. et al. (2007) Cell Death Differ 14, 1433-42.
4. Chini, C.C. et al. (2006) Oncogene 25, 4165-71.
5. Brondello, J.M. et al. (2007) Biochem Biophys Res Commun 354, 1028-33.
6. Lin, S.Y. et al. (2004) Proc Natl Acad Sci U S A 101, 6484-9.
7. Jeong, S.Y. et al. (2003) J Biol Chem 278, 46782-8.
8. Wang, X. et al. (2006) Mol Cell 23, 331-41.
9. Tsimaratou, K. et al. (2007) J Pathol 211, 331-9.

原厂资料：

Specificity / Sensitivity

Claspin Antibody detects endogenous levels of total claspin protein. 

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to amino acids near the carboxy terminus of human claspin. Antibodies are purified by peptide affinity chromatography.

Background

Originally identified in Xenopus (1), and later in human cells (2), claspin is a mediator of Chk1 signal transduction at the replication checkpoint and in response to DNA damage. Expression of claspin is cell cycle-regulated, with protein levels peaking at the S/G2 phase (2). Expression is negatively regulated by both proteosome- and caspase-mediated degradation (3), and stabilized by activation of Chk1 (4). Claspin is a chromatin-bound protein, and has been shown to interact with the PNCA complex in the absence of DNA damage (5). Following checkpoint activation it remains chromatin-bound but is released from the PCNA complex and is phosphorylated in an ATR-dependent manner. Phosphorylated claspin interacts with several components of the DNA damage response including BRCA1 (6) and Chk1 (7), leading to ATR-dependent phosphorylation on each of these proteins. Phosphorylated Rad17 has also been shown to bind to and regulate the phosphorylation of claspin (8). It has been proposed that claspin behaves as a tumor suppressor in come cases since down-regulation promotes apoptosis following genotoxic stress (2). Conversely, claspin seems to behave as an oncogene in other instances since overexpression promotes cellular proliferation (6). Upregulated claspin has been suggested to be a sensitive marker of abnormally proliferating cells (9). 

1. Kumagai, A. and Dunphy, W.G. (2000) Mol Cell 6, 839-49.
2. Chini, C.C. and Chen, J. (2003) J Biol Chem 278, 30057-62.
3. Semple, J.I. et al. (2007) Cell Death Differ 14, 1433-42.
4. Chini, C.C. et al. (2006) Oncogene 25, 4165-71.
5. Brondello, J.M. et al. (2007) Biochem Biophys Res Commun 354, 1028-33.
6. Lin, S.Y. et al. (2004) Proc Natl Acad Sci U S A 101, 6484-9.
7. Jeong, S.Y. et al. (2003) J Biol Chem 278, 46782-8.
8. Wang, X. et al. (2006) Mol Cell 23, 331-41.
9. Tsimaratou, K. et al. (2007) J Pathol 211, 331-9.

注意事项：

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM
NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C.
Do not aliquot the antibody