RESUMEN
Fanconi anemia is a genetic disease characterized by genomic instability and cancer predisposition. Nine genes involved in Fanconi anemia have been identified; their products participate in a DNA damage-response network involving BRCA1 and BRCA2 (refs. 2,3). We previously purified a Fanconi anemia core complex containing the FANCL ubiquitin ligase and six other Fanconi anemia-associated proteins. Each protein in this complex is essential for monoubiquitination of FANCD2, a key reaction in the Fanconi anemia DNA damage-response pathway. Here we show that another component of this complex, FAAP250, is mutant in individuals with Fanconi anemia of a new complementation group (FA-M). FAAP250 or FANCM has sequence similarity to known DNA-repair proteins, including archaeal Hef, yeast MPH1 and human ERCC4 or XPF. FANCM can dissociate DNA triplex, possibly owing to its ability to translocate on duplex DNA. FANCM is essential for monoubiquitination of FANCD2 and becomes hyperphosphorylated in response to DNA damage. Our data suggest an evolutionary link between Fanconi anemia-associated proteins and DNA repair; FANCM may act as an engine that translocates the Fanconi anemia core complex along DNA.
Asunto(s)
Archaea/química , ADN Helicasas/genética , Reparación del ADN , Anemia de Fanconi/genética , Hemaglutininas Virales/genética , Ligasas/genética , Proteínas Virales de Fusión/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Evolución Biológica , ADN/metabolismo , ADN Helicasas/deficiencia , ADN Helicasas/metabolismo , Anemia de Fanconi/enzimología , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi , Proteína del Grupo de Complementación L de la Anemia de Fanconi , Humanos , Inmunoprecipitación , Ligasas/deficiencia , Ligasas/metabolismo , Datos de Secuencia Molecular , Mutación , Proteínas Nucleares/metabolismo , Fosforilación , Transporte de Proteínas , Ubiquitina/metabolismo , Proteínas Virales de Fusión/deficienciaRESUMEN
The dendritic cell (DC), a most potent antigen-presenting cell, plays a key role in vaccine therapy against infectious diseases and malignant tumors. Although advantages of viral vectors for vaccine therapy have been reported, potential risks for adverse effects prevent them from being licensed for clinical use. Human parainfluenza virus type 2 (hPIV2), one of the members of the Paramyxoviridae family, is a nonsegmented and negative-stranded RNA virus. We have developed a reverse genetics system for the production of infectious hPIV2 lacking the F gene (hPIV2ΔF), wherein various advantages for vaccine therapy exist, such as cytoplasmic replication/transcription, nontransmissible infectivity, and extremely high transduction efficacy in various types of target cells. Here we demonstrate that hPIV2ΔF shows high transduction efficiency in human DCs, while not so high in mouse DCs. In addition, hPIV2ΔF sufficiently induces maturation of both human and murine DCs, and the maturation state of both human and murine DCs is almost equivalent to that induced by lipopolysaccharide. Moreover, alkylating agent ß-propiolactone-inactivated hPIV2ΔF (BPL-hPIV2ΔF) elicits DC maturation without viral replication/transcription. These results suggest that hPIV2ΔF may be a useful tool for vaccine therapy as a novel type of paramyxoviral vector, which is single-round infectious vector and has potential adjuvant activity.