Garg Renu, Geng Chuan-Dong, Miller Jennifer L, Callens Shannon, Tang Xi, Appel Bruce, Xu Bo
Department of Genetics and Stanley S. Scott Cancer Center, LSU Health Sciences Center, Room 406 CSRB Building, 533 Bolivar Street, New Orleans, LA 70112, USA.
Mol Cancer Res. 2004 Jun;2(6):348-53.
Inherited biallelic mutations of the ATM (ataxia-telangiectasia mutated) gene in humans cause ataxia-telangiectasia, a rare autosomal recessive disorder associated with progressive neuro-degeneration, cancer predisposition, immunodeficiency, and hypersensitivity to ionizing radiation. The ATM gene is highly conserved across a wide range of species. In an attempt to establish a zebrafish (Danio rerio) model of ataxia-telangiectasia, we cloned the coding sequence of the catalytic domain of the zebrafish homologue of ATM and found it to contain an open reading frame encoding 907 amino acids at the carboxyl terminus of the zebrafish ATM (zATM). The catalytic domain of zATM shares 67% and 66% homology with human ATM (hATM) and mouse ATM (mATM), respectively. The full-length mRNA encoding zATM is found to be approximately 11 kb by Northern hybridization, and the expression of zATM is observed in different adult and embryonic tissues. Overexpression of a kinase-inactive zATM domain in human cells has a dominant-negative effect against hATM function. Expression of the altered zATM in ZF4 cells leads to an A-T-like phenotype in response to ionizing radiation. These results taken together indicate that zATM is the homologue of hATM. Furthermore, using the kinase-inactive form of zATM should allow manipulation of zATM function in fish cells.
人类ATM(共济失调毛细血管扩张症突变)基因的双等位基因突变会导致共济失调毛细血管扩张症,这是一种罕见的常染色体隐性疾病,与进行性神经退行性变、癌症易感性、免疫缺陷以及对电离辐射过敏有关。ATM基因在广泛的物种中高度保守。为了建立共济失调毛细血管扩张症的斑马鱼(Danio rerio)模型,我们克隆了斑马鱼ATM同源物催化结构域的编码序列,发现其在斑马鱼ATM(zATM)的羧基末端包含一个编码907个氨基酸的开放阅读框。zATM的催化结构域与人类ATM(hATM)和小鼠ATM(mATM)的同源性分别为67%和66%。通过Northern杂交发现编码zATM的全长mRNA约为11 kb,并且在不同的成年和胚胎组织中观察到zATM的表达。在人类细胞中过表达激酶失活的zATM结构域对hATM功能具有显性负效应。在ZF4细胞中表达改变的zATM会导致对电离辐射产生类似A-T的表型。综合这些结果表明zATM是hATM的同源物。此外,使用激酶失活形式的zATM应该能够在鱼类细胞中操纵zATM的功能。