RESUMO
Colony initiation of filamentous fungi commonly involves fusion of germinating vegetative spores. Studies in Neurospora crassa revealed an unusual cell-cell communication mechanism mediating this process, in which the fusion partners coordinately alternate between two physiological stages, probably related to signal sending and receiving. This "cell dialog" involves the alternating, oscillatory recruitment of the SO protein and the MAK-2 MAP kinase module to the apical plasma membrane of growing fusion tips. In this review video article, we show the dynamics of the fluorescent labeled proteins SO and MAK-2 and provide an animated graphical model of the "cell dialog" process.
Assuntos
Hifas/genética , Sistema de Sinalização das MAP Quinases/genética , Neurospora crassa/genética , Esporos Fúngicos/genética , Comunicação Celular/genética , Membrana Celular/genética , Proteínas Fúngicas/genética , Hifas/crescimento & desenvolvimento , Neurospora crassa/crescimento & desenvolvimento , Proteínas Quinases/genética , Esporos Fúngicos/crescimento & desenvolvimentoRESUMO
The fungal vacuole is an organelle, which adopts pleiotropic morphologies and functions. In aging and starving hyphae it is the compartment of degradation and recycling of cellular constituents. Here we identified TSP3, one of three tetraspanins present in the filamentous ascomycete fungus Neurospora crassa, as a vacuolar membrane protein. The protein is detected only in aging and starving cultures and under other conditions, which induce autophagy, such as vegetative incompatibility or the presence of the macrolide antibiotic rapamycin. Mutant analysis revealed that TSP3 is dispensable for growth and development of the fungus under laboratory conditions. Together these findings indicate that tsp3 shares characteristics with idi (induced during incompatibility) genes and might promote vacuolar functions related to autophagy.
Assuntos
Proteínas Fúngicas/metabolismo , Proteínas de Membrana/metabolismo , Neurospora crassa/metabolismo , Tetraspaninas/metabolismo , Vacúolos/metabolismo , Proteínas Fúngicas/genética , Proteínas de Membrana/genética , Neurospora crassa/genética , Neurospora crassa/crescimento & desenvolvimento , Tetraspaninas/genética , Vacúolos/genéticaRESUMO
In recent years, the filamentous fungus Neurospora crassa has advanced as a model organism for studying eukaryotic cell-cell communication and fusion. Cell merger in this fungus employs an unusual mode of communication, in which the fusion partners appear to switch between signal sending and receiving. Many molecular factors mediating this intriguing mechanism and the subsequent membrane merger have been identified. It has become apparent that conserved factors, such as MAP kinases, NADPH oxidases and the STRIPAK complex, together with fungal specific proteins are wired into an intricate signaling network. Here, we will present an overview of recent findings on the molecular mechanism mediating fusion in N. crassa and will discuss the current working model.