INVESTIGADORES
MORENO Silvia Margarita
artículos
Título:
Mucor rouxii ultrastructure: cAMP and actin cytoskeleton
Autor/es:
PEREYRA, E., INGERFELD, M., ANDERSON, N., JACKSON, SL AND MORENO, S.
Revista:
PROTOPLASMA
Editorial:
Springer Wien
Referencias:
Lugar: Viena; Año: 2005 p. 1 - 1
ISSN:
0033-183X
Resumen:
A comparative analysis of the effect of two compounds: dibutyrylcAMP and Latrunculin B on the morphology and ultrastructure of the dimorphic fungus Mucor rouxii, under aerobic growth conditions, is presented. DibutyrylcAMP acts through the sustained activation of protein kinase A, and latrunculin B, through the disruption of actin cytoskeleton. Upon addition of the compounds to the growth medium, at any stage of the germination process,  cell lose polarised growth and switch to isodiametric growth. The effect is reversible. The morphologies, visualised by light microscopy or scanning electron microscopy (SEM) are alike. A switch from rough to smooth surface is observed by  SEM when cells are repolarised by removal of the added compound. Ultrastracture under both conditions, as observed by transmission electron microscopy, are almost alike being the main feature the enlargement of the cell wall, with irregular depositions, and detachment from the cell membrane. DibutyrylcAMP treated cells lose the glycogen granules observed in control and Latrunculin B treated cells. The results suggest that the sustained activation of PKA, which impairs polarised growth impacts reversibly on the actin filament organization. The effect might be direct or indirect, in cross talk with integrin-like pathway with which we have demonstrated cAMP pathway is connected to (E Pereyra et al, 2003, Protoplasma 222: 22-30).