The ataxia-telangiectasia disease protein ATM controls vesicular protein secretion via CHGA and microtubule dynamics via CRMP5

Ataxia telangiectasia mutated (ATM) is a protein that belongs to the family of phosphatidylinositol 3-kinase (PI3K)-like serine/threonine kinases. Initially identified as a nuclear protein essential for the DNA damage response (DDR) in mitotic cells, it serves as repair coordinator for DNA double-strand breaks (DSBs). Dysfunction of the ATM protein underlies ataxia telangiectasia (A-T), a rare autosomal recessive disorder characterized by immunodeficiency and progressive cerebellar degeneration leading to ataxia. The cause of cerebellar neurodegeneration cannot be explained at present, given that in postmitotic neurons ATM has a cytoplasmic localization. The non-nuclear functions of ATM and their mechanistic link to cerebellar degeneration in A-T remain elusive. In this study we established both phosphoproteomic and proteomic profiles of ATM deficiency in neuroblastoma cells and mouse cerebellum tissue to identify the underlying molecular mechanism and relevant signaling networks.