CHK1, Chk1 Checkpoint homolog

名称: CHK1/CHEK1；细胞周期检测点激酶1 种属：human

描述: 1. One mechanism by which checkpoints maintain the fidelity of cell cycle events is through blocking mitosis in response to unreplicated or damaged DNA. In most species this occurs through inhibiting activation of the cyclic dependent kinase Cdc2, which regulates entry into mitosis. Chk1, a kinase involved in the DNA damage checkpoint response can phosphorylate Cdc25C an activator of Cdc2. It is hypothesized that Chk1 induces serine 216 phosphorylation of Cdc25C and subsequent 14-3-3 binding negatively regulated Cdc25C, thus preventing it from activating Cdc2.

2. DNA damage or incomplete replication of DNA results in the inhibition of cell cycle progression at the G1 to S or the G2 to M phase transition by conserved regulatory mechanisms known as cell cycle checkpoints. Checkpoint proteins include Rad17, which is involved in regulating cell cycle progression at the G1 checkpoint, and Chk1, Chk2, Rad1, Rad9 and Hus1, which are involved in regulating cell cycle arrest at the G2 checkpoint. Overexpression of Rad17 results in the activation of p53 and an accumulation of cells in G1. Bub1 is involved in cell cycle checkpoint enforcement while Bub2 is part of a checkpoint that prevents premature exit from mitosis and monitors spindle integrity

Robert Abraham博士和同事发现Chk1蛋白与由组织缺氧和特定的抗癌药物引起的压力条件下的细胞存活有关。而且，这些相同状况靶向Chk1并导致最终的破坏。Chk1的活化引发能够抵御癌症的特定的修复反应，尽管Chk1的刺激性降解能使癌细胞逃脱药物诱导的死亡并重新开始侵略性的肿瘤生长。

研究表明Chk1蛋白对确保DNA复制过程中的突变和其他错误在改变整个细胞功能前加以修复是至关重要的。如果不能修复，这些错误就能够在细胞分裂和扩增时杀死它。在癌细胞中，Chk1充当一种天然的防御物质以预防由化疗和放疗导致的治疗性损伤并试图修复由抗癌治疗导致的DNA损伤，从而使得药物失效。

研究人员还发现化疗药剂CPT（重要的抗癌药物）能够降低Chk1蛋白的活性。这些发现强有力地证明了Chk1的失活通过使细胞耐受损伤的DNA并继续完成细胞周期并最终导致细胞死亡来促进CPT的抗肿瘤活性。这些发现还为进一步分析Chk1的活性和肿瘤的敏感性提供了重要信息。

参考文献: #:Cdk5 is essential for adult hippocampal neurogenesis. Proc Natl Acad Sci U S A. 2008 Nov 25;105(47)

病毒转染实验的重要性

病毒转染实验是研究目的基因、目的蛋白功能极其有效的分子生物学方法， 其原理是构建过表达或者iRNA干扰病毒质粒，根据实验需要，分别包装成腺病毒、慢病毒、逆转录病毒，感染宿主细胞或动物组织，调控宿主细胞或动物组织相应基因表达及蛋白合成，为了解目的基因及蛋白对细胞功能的调控提供了有利的手段，广泛受到科研工作者重视及青睐，成为分子机制研究不可缺少的重要实验手段。

服务优势：

一、一站式全套服务：可根据客户的要求，提供从克隆、病毒包装、细胞转染到稳定株筛选，直至完成体内外实验。

二、周期快：上千次病毒转染实验承接，使我们的管理、技术都达到了一个新的台阶，目前我们能够在保证优质服务的基础上，4周左右完成全部实验（含建系），极大缩短实验时间，为广大科研工作者节约宝贵的科研时间。

三、客户风险低：保证实验成功

四、售前售后服务全: 上海地区免费上门服务，负责到您满意为止