Elucidating the role of mai1 in cell cycle control and DNA damage response

描述（由申请人提供）：细胞通过激活导致细胞周期停滞、DNA 修复和凋亡的信号转导途径来响应 DNA 损伤。 DNA 损伤检查点对于维持基因组完整性至关重要。 DNA 损伤反应在人类病理学，尤其是癌症中的重要性是众所周知的。编码 DNA 损伤检查点蛋白的各种基因的突变与多种人类疾病综合征相关，这些综合征的特征通常是增加患癌症的倾向。尽管在理解 DNA 损伤检查点方面已经取得了重大进展，但构成 DNA 损伤反应的途径网络很复杂，并且其他成分仍有待识别。我们筛选了突变斑马鱼胚胎的 DNA 损伤反应缺陷。这确定了两个突变株系在暴露于电离辐射后未能阻止有丝分裂进入。这些细胞系中的每一个都携带一个基因突变，我们将其命名为mail（辐射后有丝分裂1）。邮件基因编码一种与其他脊椎动物（包括人类）的直系同源蛋白。这些物种中存在高度保守的氨基酸块，但没有表明潜在生物学功能的基序或结构域。除了检查点表型外，未经辐射的邮件斑马鱼在正常细胞周期进展方面也存在缺陷。该提案的目标是确定 Mail 在细胞周期调节和 DNA 损伤检查点中的作用。具体目标有两个：（1）研究邮件斑马鱼突变体的DNA损伤检查点和细胞周期缺陷； (2) 建立人类细胞中邮件的功能。

DESCRIPTION (provided by applicant): Cells respond to DNA damage by activating signal transduction pathways that lead to cell cycle arrest, DNA repair and apoptosis. DNA damage checkpoints are essential for the maintenance of genomic integrity. The importance of the DNA damage response in human pathology, especially cancer, is well established. Mutations in various genes encoding DNA damage checkpoint proteins are associated with a variety of human disease syndromes and these are often characterized by an increased predisposition to cancer. Although significant progress has been made understanding DNA damage checkpoints, the network of pathways that compose the DNA damage response is complex and additional components remain to be identified. We have screened mutant zebrafish embryos for DNA damage response defects. This identified two mutant lines that fail to arrest mitotic entry following exposure to ionizing radiation. Each of these lines carries a mutation in a gene that we have named mail (mitosis after irradiation 1). The mail gene encodes a protein with orthologues in other vertebrate species, including humans. There are blocks of amino acids that are highly conserved across these species, but no motifs or domains to suggest a potential biological function. In addition to a checkpoint phenotype, unirradiated mail zebrafish have a defect in normal cell cycle progression. The goal of this proposal is to determine Mail's role in cell cycle regulation and DNA damage checkpoints. There are two specific aims: (1) to investigate the DNA damage checkpoint and cell cycle defects of mail zebrafish mutants; and (2) to establish the function of Mail in human cells.