IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
SUB-NUCLEAR IRRADIATION, IN-VIVO MICROSCOPY AND SINGLE-MOLECULE IMAGING TO STUDY A DNA POLYMERASE
Autor/es:
SORIA G; MANSILLA S; BELLUSCIO L; SPERONI J; D' ALESSIO C; ESSERS J; KANAAR R; GOTTIFREDI V
Lugar:
San MIguel de Tucumán, Tucumán, Argentina
Reunión:
Congreso; 45 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2009
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
When the DNA is damaged in cells progressing through S phase,
replication blockage can be avoided by TLS (Translesion DNA
synthesis). This is an auxiliary replication mechanism that relies on
the function of specialized polymerases that accomplish DNA
damage bypass. An example of a classical TLS polymerase is Pol
h(eta). The current model implies that Pol h activity is
circumscribed to S-phase. Here we perform a systematic
characterization of Pol h behaviour after DNA-damage. We show
that Pol h is recruited to UV-induced DNA lesions in cells outside S
phase including cells permanently arrested in G1. This observation
was confirmed by different sub-nuclear damage strategies including
global UV irradiation, local UV irradiation and local multi-photon
laser irradiation of single nuclei in living cells. By local UV
irradiation and alpha particle irradiation we evaluated the potential
connection between Pol h recruitment to DNA lesions outside S
phase and Homologous recombination repair (HRR) or Nucleotide
excision repair (NER). Finally, we employ a single-molecule
imaging approach (known as DNA fiber-assay) to determine how
Pol h influences the progression of the replication fork. Our data
reveals that the re-localization of Pol h to DNA lesions might be
temporally and mechanistically uncoupled from replicative DNA
synthesis and from DNA damage processing.