title: A single mutation in Securin induces chromosomal instability and enhances cell invasion.
abstract: Pituitary tumour transforming gene (pttg1) encodes Securin, a protein involved in the inhibition of sister chromatid separation binding to Separase until the onset of anaphase. Separase is a cysteine-protease that degrades cohesin to segregate the sister chromatids to opposite poles of the cell. The amount of Securin is strongly regulated because it should allow Separase activation when it is degraded by the anaphase promoting complex/cyclosome, should arrest the cell cycle after DNA damage, when it is degraded through SKP1-CUL1-βTrCP ubiquitin ligase, and its overexpression induces tumour formation and correlates with metastasis in multiple tumours. Securin is a phosphoprotein that contains 32 potentially phosphorylatable residues. We mutated and analysed most of them, and found a single mutant, hSecT60A, that showed enhanced oncogenic properties. Our fluorescence activated cell sorting analysis, fluorescence in situ hybridisation assays, tumour cell migration and invasion experiments and gene expression by microarrays analysis clearly involved hSecT60A in chromosomal instability and cell invasion. These results show, for the first time, that a single mutation in pttg1 is sufficient to trigger the oncogenic properties of Securin. The finding of this point mutation in patients might be used as an effective strategy for early detection of cancer.
authors: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain.
authors: Mar
authors: M
authors: Mora-Santos
authors: Carolina
authors: C
authors: Castilla
authors: Joaquín
authors: J
authors: Herrero-Ruiz
authors: Servando
authors: S
authors: Giráldez
authors: M Cristina
authors: MC
authors: Limón-Mortés
authors: Carmen
authors: C
authors: Sáez
authors: Miguel Á
authors: MÁ
authors: Japón
authors: Maria
authors: M
authors: Tortolero
authors: Francisco
authors: F
authors: Romero
mesh_terms: D000818:Animals; D019556:COS Cells; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002522:Chlorocebus aethiops; D043171:Chromosomal Instability; D015870:Gene Expression; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D046228:Microarray Analysis; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D017354:Point Mutation; D064249:Securin; D013912:Threonine / Q000235:genetics; D014162:Transfection
chemical_list: D009363:Neoplasm Proteins; D064249:Securin; C578002:pituitary tumor-transforming protein 1, human; D013912:Threonine