title: HMGA1 protein is a novel target of the ATM kinase.
abstract: The high mobility group HMGA1 protein belongs to a family of architectural factors that play a role in chromosomal organisation and gene transcription regulation. HMGA1 overexpression represents a common feature of human malignant tumours and is causally associated with neoplastic transformation and metastatic progression. Recently, HMGA1 expression has been correlated with the presence of chromosomal rearrangements and suggested to promote genomic instability. Here, we report a novel interaction between HMGA1 protein and the ataxia-telangiectasia mutated (ATM) kinase, the major key player in the cellular response to DNA damage caused by several agents such as ionising radiation (IR). We identified an SQ motif on HMGA1, which is effectively phosphorylated by ATM in vitro and in vivo. Interestingly, confocal microscopy revealed that HMGA1 colocalises with the activated form of ATM (ATM S1981p). Moreover, HMGA1 ectopic expression decreases cell survival following exposure to IR as assessed by clonogenic survival in MCF-7 cells, further supporting the hypothesis that HMGA1 might act as a downstream target of the ATM pathway in response to DNA damage.
authors.affiliation: Istituto di Endocrinologia ed Oncologia Sperimentale del CNR c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli Federico II, Naples, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pentimalli
authors.forename: Dario
authors.initials: D
authors.lastname: Palmieri
authors.forename: Roberto
authors.initials: R
authors.lastname: Pacelli
authors.forename: Corrado
authors.initials: C
authors.lastname: Garbi
authors.forename: Rossano
authors.initials: R
authors.lastname: Cesari
authors.forename: Eric
authors.initials: E
authors.lastname: Martin
authors.forename: Giovanna Maria
authors.initials: GM
authors.lastname: Pierantoni
authors.forename: Paolo
authors.initials: P
authors.lastname: Chieffi
authors.forename: Carlo Maria
authors.initials: CM
authors.lastname: Croce
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Costanzo
authors.forename: Monica
authors.initials: M
authors.lastname: Fedele
authors.forename: Alfredo
authors.initials: A
authors.lastname: Fusco
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000502:physiology; D004249:DNA Damage / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D025741:HMGA1a Protein / Q000378:metabolism* / Q000528:radiation effects; D006801:Humans; D009369:Neoplasms / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011839:Radiation, Ionizing; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D025521:Tumor Suppressor Proteins; D025741:HMGA1a Protein; C576324:ATM protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases