INVESTIGADORES
KURTH daniel German
congresos y reuniones científicas
Título:
Physiological, genomic and proteomic evidences support the high UV resistance profile of Acinetobacter sp. Ver3 isolated from High Altitude Andean Lakes
Autor/es:
KURTH, D; ALBARRACIN, VH; BELFIORE, C; GORRITI, MF; FARIAS, ME
Lugar:
San Carlos de Bariloche
Reunión:
Congreso; V Congreso Argentino de Bioinformática y Biología Computacional; 2014
Institución organizadora:
AB2C2 y el Instituto de Energía y Desarrollo Sustentable (IEDS), Centro Atómico Bariloche (CNEA)
Resumen:
High-Altitude Andean Lakes (HAAL) are a group of disperse shallow lakes
and salterns, located at the Dry Central Andes region in South America
at altitudes above 3,000 m, and exposed to a unique combination of
severe conditions: i.e. high solar global and UV irradiation,
hypersalinity, wide fluctuations in daily temperatures, desiccation,
high pH, high concentrations of toxic elements including arsenic [1]. As
it is considered one of the highest UV-exposed environments on Earth,
HAAL microbes can be taken as model systems to study UV-resistance
mechanisms in environmental bacteria at various complexity levels.
Acinetobacter sp. Ver3, a gammaproteobacteria isolated from Laguna Verde
(4,400 m) was recently proposed as a model UV-resistant microbe with
highly efficient DNA damage photorepairing ability [2], as well as an
efficient catalase machinery [3]. Here we present the genome sequence
analyses of this extremophile together with further experimental
evidence supporting the idea that this bacterium is able to cope with
increased damage in DNA compared to sensitive strains. The genome
analyses provided insight in the taxonomic classification of this
organism, suggesting that it would be a new species, and allowed to
identify resistance genes related to the harsh environment. Moreover, an
?UV-resistome? was defined, encompassing genes related to UV-damage
repair on DNA (such as nucleases and glycosylases from excision repair
systems), and genes conferring an enhanced capacity for scavenging the
reactive molecular species responsible for oxidative damage (catalases,
peroxidases and SODs). In addition, the UV response was also studied at
the proteomic level, which confirmed the involvement of a specific
cytoplasmic catalase, a putative regulator, and proteins associated to
aminoacid and protein synthesis, among others. However, only a small
number of proteins were overexpressed under UV stress, suggesting that
the resistance of this bacterium might be due to efficient
constitutively expressed systems.References1. Farias ME,
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Tewari V, Seckbach J. Dordrecht: Springer Netherlands; 2011:427?441.
[Cellular Origin, Life in Extreme Habitats and Astrobiology]2.
Albarracín VH, Pathak GP, Douki T, Cadet J, Borsarelli CD, Gärtner W,
Farias ME: Extremophilic Acinetobacter strains from high-altitude lakes
in Argentinean Puna: remarkable UV-B resistance and efficient DNA damage
repair. Orig Life Evol Biosph 2012, 42:201?21.3. Di Capua C,
Bortolotti A, Farías ME, Cortez N: UV-resistant Acinetobacter sp.
isolates from Andean wetlands display high catalase activity. FEMS
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