title: ATM blocks tunicamycin-induced endoplasmic reticulum stress.
abstract: Endoplasmic reticulum stress (ER-stress) is associated with ataxia telangiectasia mutated (ATM) gene. We present here conclusive data showing that ATM blocks ER-stress induced by tunicamycin or ionizing radiation (IR). X-box protein-1 (XBP-1) splicing, GRP78 expression and caspase-12 activation were increased by tunicamycin or IR in Atm-deficient AT5BIVA fibroblasts. Activation of caspase-12 and caspase-3 by tunicamycin was significantly reduced in cells transfected with wild-type Atm (AT5BIVA/wtATM). Atm knockdown by siRNA, however, noticeably elevated ER-stress and chemosensitivity to tunicamycin. In summary, we present substantial data demonstrating that ATM blocks the ER stress signaling associated with cancer cell proliferation.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong, Daejeon 305-806, Republic of Korea.
authors.forename: Long
authors.initials: L
authors.lastname: He
authors.forename: Sun Ok
authors.initials: SO
authors.lastname: Kim
authors.forename: Osong
authors.initials: O
authors.lastname: Kwon
authors.forename: Sook Jung
authors.initials: SJ
authors.lastname: Jeong
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Kim
authors.forename: Hee Gu
authors.initials: HG
authors.lastname: Lee
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada
authors.forename: Mira
authors.initials: M
authors.lastname: Jung
authors.forename: Jong Seog
authors.initials: JS
authors.lastname: Ahn
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D064007:Ataxia Telangiectasia Mutated Proteins; D053454:Caspase 12 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism* / Q000528:radiation effects; D000091342:Endoplasmic Reticulum Chaperone BiP; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D013312:Stress, Physiological / Q000187:drug effects* / Q000528:radiation effects; D025521:Tumor Suppressor Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; D014415:Tunicamycin; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D053454:Caspase 12; D053148:Caspase 3