The phosphatidylinositol kinase (PIK) family members fall into two distinctsubgroups. The first subgroup contains proteins such as the PI 3- and PI 4-kinases and the second group comprises the PIK-related kinases. The PIKrelatedkinases include Atm, DNA-PKCS and FRAP. These proteins have incommon a region of homology at their carboxy-termini that is not present inthe PI 3- and PI 4-kinases. The Atm gene is mutated in the autosomal recessivedisorder ataxia telangiectasia (AT) that is characterized by cerebellardegeneration (ataxia) and the appearance of dilated blood vessels (telangiectases)in the conjunctivae of the eyes. AT cells are hypersensitive to ionizingradiation, impaired in mediating the inhibition of DNA synthesis and theydisplay delays in p53 induction. Cultured cells respond to breaks in doublestranded DNA by immediate activation of ATM through autophosphorylationon Serine 1981. Most human tissues, however, contain the non-phosphorylated,inactive form of Atm.蚂蚁淘在线声明：以上所展示的信息由企业自行提供，内容的真实性、准确性和合法性由发布企业负责。蚂蚁淘在线对此不承担任何保证责任。