title: An Amylase-Like Protein, AmyD, Is the Major Negative Regulator for α-Glucan Synthesis in Aspergillus nidulans during the Asexual Life Cycle.
abstract: α-Glucan affects fungal cell-cell interactions and is important for the virulence of pathogenic fungi. Interfering with production of α-glucan could help to prevent fungal infection. In our previous study, we reported that an amylase-like protein, AmyD, could repress α-glucan accumulation inAspergillus 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 α-glucan degradation, as well as with other predicted amylase-like proteins and three annotated α-glucanases. AmyC and AmyE share a substantial sequence identity with AmyD, however, neither affects α-glucan synthesis. In contrast, AgnB and MutA (but not AgnE) are functional α-glucanases that also repress α-glucan accumulation. Nevertheless, the functions of AmyD and these glucanases were independent from each other. The dynamics of α-glucan accumulation showed different patterns between the AmyD overexpression strain and the α-glucanase overexpression strains, suggesting AmyD may not be involved in the α-glucan degradation process. These results suggest the function of AmyD is to directly suppress α-glucan synthesis, but not to facilitate its degradation.
authors.affiliation: Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, Jilin, China. hexx100@nenu.edu.cn.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.affiliation: Jilin Institute of Biology, Changchun 130012, Jilin, China. lishengnan8435@hotmail.com.
authors.forename: Shengnan
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada. susan.kaminskyj@usask.ca.
authors.forename: Susan
authors.initials: S
authors.lastname: Kaminskyj
mesh_terms: D000681:Amylases / Q000235:genetics / Q000378:metabolism*; D001233:Aspergillus nidulans / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D001557:Benzenesulfonates / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005936:Glucans / Q000096:biosynthesis*; D005947:Glucose / Q000494:pharmacology; D008018:Life Cycle Stages; D018613:Microscopy, Confocal
chemical_list: D001557:Benzenesulfonates; D005656:Fungal Proteins; D005936:Glucans; C007061:C.I. Fluorescent Brightening Agent 28; D000681:Amylases; D005947:Glucose
keywords: A. nidulans; AmyD; cell wall; fungal virulence; α-glucan