INBA   12521
INSTITUTO DE INVESTIGACIONES EN BIOCIENCIAS AGRICOLAS Y AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
TRANSCRIPTIONAL CROSS-REGULATION BETWEEN CANDIDA ALBICANS TPK1 AND BCY1 GENES
Autor/es:
GIACOMETTI ROMINA; KRONBERG FLORENCIA; PASSERON SUSANA
Lugar:
San Miguel de Tucuman, Tucuman
Reunión:
Congreso; XLV Reunión Anual SAIB; 2009
Institución organizadora:
SAIB
Resumen:
In the present study, we performed a series of physiological and biochemical studies of a set of new generated Candida albicans PKA mutant strains, null for TPK2 and carrying heterozygous TPK1 and/or BCY1 alleles. The combination of deletions in strain tpk2 TPK1/tpk1 BCY1/bcy1 rendered a mutant widely affected in its ability to react to changes in the environment, including dimorphism and biofilm formation. In vitro kinase assays along the growth curve showed that the defective new mutant, which exhibited an extremely low PKA specific activity at the stationary phase, vastly increased its specific activity at the logarithmic stage of growth which was not accompanied by a significant increase in neither mRNA transcription nor protein synthesis, suggesting a transient activation of enzyme activity. A  TPK1 reintegrated version of this mutant strain showed a phenotype similar to that of parental strain  tpk2/tpk2 BCY1/bcy1. However, restoration of TPK1 copy surprisingly led to an upregulation of BCY1 transcript. Increased cAMP binding levels consistent with the compensatory expression of the regulatory subunit were observed in this mutant. These results suggest an unexpected complex interdependence of the biosynthesis of the Tpk1 catalytic isoform and the Bcy1 regulatory subunit, whose molecular basis remains to be established.Supported by grants from CONICET and ANPCyT.