INVESTIGADORES
COMELLI Raul Nicolas
congresos y reuniones científicas
Título:
The Arabidopsis cytc-2 gene is regulated by the cooperative action of siteII and G-box motifs
Autor/es:
WELCHEN E, VIOLA , COMELLI RN, GONZÁLEZ DH
Lugar:
Mar del Plata, Argentina
Reunión:
Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2007
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)
Resumen:
The Arabidopsis cytc-2 (At4g10040) gene has been shown
to be upregulated in response to carbohydrates, cicloheximide and under stress
conditions. Progressive deletions and base substitution analysis of the cytc-2 promoter region revealed a
cooperative action between site II elements, G-box and ACGT motifs. While site
II motifs regulate the magnitude of the response to different treatments and
the basal expression in reproductive tissues, the main expression
characteristics of the cytc-2 gene
are dependent on an essential fragment (-189 to -139) containing a G-box and an
ACGT motif. These motifs regulate the response to different effectors, such as
light, carbohydrates, hormones, UV and environmental stress. By means of yeast
one-hybrid screening we identified a group of transcription factors from the
bZip and bHLH families (AtABF4, AtGBF1, AtGBF3, AtGBFlike, AtHLH080) that are
able to bind to the cytc-2 G-box
motif. Electrophoretic mobility shift assays using nuclear extracts indicated
that the integrity of the region from -149 to -139 is required for efficient
binding of proteins to the G-box motif, suggesting the existence of cooperative
interactions. We conclude that site II motifs and the G-box, interacting with
several transcription factors, are involved in determining specific aspects of
the cytc-2 expression patterns.