An Amylase-Like Protein, AmyD, Is the Major Negative Regulator for ?-Glucan Synthesis in Aspergillus nidulans during the Asexual Life Cycle.

ABSTRACT: ?-Glucan affects fungal cell-cell interactions and is important for the virulence of pathogenic fungi. Interfering with production of ?-glucan could help to prevent fungal infection. In our previous study, we reported that an amylase-like protein, AmyD, could repress ?-glucan accumulation in Aspergillus nidulans. However, the underlying molecular mechanism was not clear. Here, we examined the localization of AmyD and found it was a membrane-associated protein. We studied AmyD function in ?-glucan degradation, as well as with other predicted amylase-like proteins and three annotated ?-glucanases. AmyC and AmyE share a substantial sequence identity with AmyD, however, neither affects ?-glucan synthesis. In contrast, AgnB and MutA (but not AgnE) are functional ?-glucanases that also repress ?-glucan accumulation. Nevertheless, the functions of AmyD and these glucanases were independent from each other. The dynamics of ?-glucan accumulation showed different patterns between the AmyD overexpression strain and the ?-glucanase overexpression strains, suggesting AmyD may not be involved in the ?-glucan degradation process. These results suggest the function of AmyD is to directly suppress ?-glucan synthesis, but not to facilitate its degradation.

SUBMITTER: He X 

PROVIDER: S-EPMC5412281 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature