LaeA is a global regulator of secondary metabolism in Aspergillus spp. It controls the expression of gene clusters responsible for producing secondary metabolites such as sterigmatocystin (ST), penicillin (PN), and lovastatin (LOV). Deletion of laeA blocks the expression of these gene clusters, while overexpression increases their transcription and product formation. LaeA is negatively regulated by AflR, a Zn²Cys₆ transcription factor, and by two signal transduction elements, protein kinase A and RasA. Despite these regulatory mechanisms, ΔlaeA strains show little difference in spore production compared to the wild type, indicating that LaeA's primary role is in regulating metabolic gene clusters. Secondary metabolites are important for fungal development and have significant biotechnological and pharmaceutical applications. Many of these compounds have useful antibiotic, antiviral, antitumor, and immunosuppressant properties, as well as toxic effects. The discovery of global regulators for fungal secondary metabolite production is critical for manipulating their biosynthesis. LaeA is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development. LaeA is a nuclear protein that is required for the expression of secondary metabolite genes. It is involved in the transcriptional regulation of secondary metabolism gene clusters. LaeA is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development. LaeA is a global regulator of secondary metabolism in Aspergillus spp. It is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development.LaeA is a global regulator of secondary metabolism in Aspergillus spp. It controls the expression of gene clusters responsible for producing secondary metabolites such as sterigmatocystin (ST), penicillin (PN), and lovastatin (LOV). Deletion of laeA blocks the expression of these gene clusters, while overexpression increases their transcription and product formation. LaeA is negatively regulated by AflR, a Zn²Cys₆ transcription factor, and by two signal transduction elements, protein kinase A and RasA. Despite these regulatory mechanisms, ΔlaeA strains show little difference in spore production compared to the wild type, indicating that LaeA's primary role is in regulating metabolic gene clusters. Secondary metabolites are important for fungal development and have significant biotechnological and pharmaceutical applications. Many of these compounds have useful antibiotic, antiviral, antitumor, and immunosuppressant properties, as well as toxic effects. The discovery of global regulators for fungal secondary metabolite production is critical for manipulating their biosynthesis. LaeA is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development. LaeA is a nuclear protein that is required for the expression of secondary metabolite genes. It is involved in the transcriptional regulation of secondary metabolism gene clusters. LaeA is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development. LaeA is a global regulator of secondary metabolism in Aspergillus spp. It is required for the biosynthesis of ST, PN, and other metabolites in Aspergillus species. It also regulates the expression of the LOV gene cluster in A. nidulans and native LOV expression in A. terreus. LaeA is conserved in filamentous fungi but not in Saccharomyces cerevisiae, a fungus without secondary metabolites. Unlike other genes regulating secondary metabolism, the loss of laeA has minimal impact on morphological development.