Title: | Cross-talk between the autocrine (mitogenic) pheromone loop of the ciliate Euplotes raikovi and the intracellular cyclic AMP concentration |
Author(s): | Apone F; Vallesi A; Di Pretoro B; Luporini P; |
Address: | "Dipartimento di Biologia Molecolare, Cellulare e Animale, University of Camerino, 62032, Camerino (MC), Italy" |
DOI: | 10.1016/s0014-4827(03)00017-x |
ISSN/ISBN: | 0014-4827 (Print) 0014-4827 (Linking) |
Abstract: | "Cell type-specific protein signals, called pheromones, are constitutively secreted by Euplotes raikovi and bound back in autocrine fashion, with a positive effect on the vegetative (mitotic) cell growth. In cells growing suspended with their secreted pheromone, it was found that any interruption of this autocrine signaling loop was immediately followed by an effective enhancement of the basal intracellular cyclic AMP (cAMP) level. To establish a cause-effect relationship between these pheromone-induced variations in the cytoplasmic cAMP level and cell growth, cells ready to pass from a resting stage to a new growth cycle were conditioned either to incorporate a cAMP analog resistant to phosphodiesterase degradation, or to utilize cAMP released (following cell irradiation) from incorporated 'caged' cAMP. Cells responded at every induced increase in their basal cAMP level by markedly decreasing their commitment to start a new growth cycle. It was deduced that the autocrine signaling of E. raikovi pheromones involves cAMP as inhibitor of its mitogenic activity" |
Keywords: | Adenylyl Cyclases/metabolism Amines/metabolism Animals Autocrine Communication/*physiology Cell Division/physiology Colforsin/metabolism Cyclic AMP/analogs & derivatives/*metabolism Euplotes/cytology/*physiology Pheromones/*metabolism Phosphoric Diester H; |
Notes: | "MedlineApone, Fabio Vallesi, Adriana Di Pretoro, Barbara Luporini, Pierangelo eng Research Support, Non-U.S. Gov't 2003/04/12 Exp Cell Res. 2003 Apr 15; 285(1):107-13. doi: 10.1016/s0014-4827(03)00017-x" |