INVESTIGADORES
MORENO Silvia Margarita
congresos y reuniones científicas
Título:
DELETION OF REGULATORY SUBUNIT OF PROTEIN KINASE A IN MUCOR CIRCINELLOIDES ALTERS MORPHOLOGY
Autor/es:
OCAMPO, J; SILVA, F.; PEREYRA, E; BARDECI, N.; MORENO, S; GARRE MULA, V.; ROSSI, S.
Lugar:
Mar del Plata, Buenos Aires
Reunión:
Congreso; 43 Reunion Anual SAIB; 2007
Institución organizadora:
SAIB
Resumen:
In M. circinelloides pkaR and pkaC genes, encode the regulatory and catalytic subunits of the PKA. Expression analysis during the dimorphic shift suggested a role for pkaR in the control of morphology and branching. To determine the pkaR gene functions we have constructed a mutant of M. circinelloides that lacks the pkaR, and analyzed its growth and development. Null mutant was generated by gene replacement. The knock-out vector contained the pyrG gene selective marker, flanked by sequences of the corresponding pkaR gene. Restriction fragments from the plasmid containing the pyrG gene and sequences of the corresponding pkaR gene to allow homologous recombination were used to transform protoplasts from the MU402 strain, which is wild-type for PKA but auxotrophic for uracil and leucine. The disruption of pkaR gene was confirmed by PCR, Southern, Northern and Western blot analysis. PKA and cAMP binding activities were measured in wt and mutant strains. Binding activity is reduced but not abolished and PKA activity is lower and cAMP independent in null mutant. The growth and germination rates of the mutant are reduced. The switch from isodiametric growth to tip growth in null mutant is delayed. The germ tubes are wider than those of the control. The results indicate that more than one gene codes for cAMP binding activity and that PKA is involved in Mucor morphology.