Sterol Regulatory Element-Binding Protein, BbSre1, Controls Oxidative Stress Response, Peroxisome Division, and Lipid Homeostasis in an Insect Fungal Pathogen

Sterol regulatory element-binding protein, Sre1, regulates
sterol
biosynthesis, lipid metabolism, hypoxia adaptation, and virulence
in some fungi, even though its roles are varied in fungal species.
However, few studies report its other functions in fungi. Here, we
report novel roles of Sre1 homolog, BbSre1, in the insect fungal pathogen, Beauveria bassiana, that regulates oxidative stress
response, peroxisome division, and redox homeostasis. The gene disruption
stain showed increased sensitivity to oxidative stress, which was
in line with oxidative stress-induced-BbSre1 nuclear import and control
of antioxidant and detoxification-involved genes. The gene mutation
also inhibited peroxisome division, affected redox homeostasis, and
impaired lipid/fatty acid metabolism and sterol biosynthesis, which
was verified by downregulation of their associated genes. These data
broaden our understanding of role of Sre1, which regulates peroxisome
division, antioxidant, and detoxification-involved genes for control
of redox homeostasis and oxidative stress response that links to lipid/fatty
acid metabolism and sterol biosynthesis.