| Title | Characterization of NpgA, a 4'-phosphopantetheinyl transferase of Aspergillus nidulans, and evidence of its involvement in fungal growth and formation of conidia and cleistothecia for development |
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| Author | Jung-Mi Kim1, Ha-Yeon Song1, Hyo-Jin Choi1, Kum-Kang So2, Dae-Hyuk Kim2, Keon-Sang Chae2, Dong-Min Han3, and Kwang-Yeop Jahng4* |
| Address | 1Department of Bio-Environmental Chemistry, Wonkwang University, Iksan 570-749, Republic of Korea, 2Department of Molecular Biology, Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju 561-756, Republic of Korea, 3Division of Biological Sciences, Wonkwang University, Iksan 570-749, Republic of Korea, 4Department of Biological Science, Chonbuk National University, Jeonju 561-756, Republic of Korea |
| Bibliography | Journal of Microbiology, 53(1),21-31, 2015, |
| DOI | 10.1007/s12275-015-4657-8 |
| Key Words | Aspergillus nidulans, npgA, phosphopantetheinyl transferase, metabolite, development |
| Abstract | The null pigmentation mutant (npgA1) in Aspergillus nidulans results in a phenotype with colorless organs, decreased branching growth, delayed of asexual spore development, and aberrant cell wall structure. The npgA gene was isolated from A. nidulans to investigate these pleiomorphic phenomena of npgA1 mutant. Sequencing analysis of the complementing gene indicated that it contained a 4-phosphopantetheinyl transferase (PPTase) superfamily domain. Enzymatic assay of the PPTase, encoded by the npgA gene, was implemented in vivo and in vitro. Loss-of-function of LYS5, which encoded a PPTase in Saccharomyces cerevisiae, was functionally complemented by NpgA, and Escherichia coli-derived NpgA revealed phosphopantetheinylation activity with the elaboration of 35-ADP. Deletion of the npgA gene caused perfectly a lethal phenotype and the absence of asexual/sexual sporulation and secondary metabolites such as pigments in A. nidulans. However, a cross feeding effect with A. nidulans wild type allowed recovery from deletion defects, and phased-culture filtrate from the wild type were used to verify that the npgA gene was essential for formation of metabolites needed for development as well as growth. In addition, forced expression of npgA promoted the formation of conidia and cleistothecia as well as growth. These results indicate that the npgA gene is involved in the phosphopantetheinylation required for primary biological processes such as growth, asexual/sexual development, and the synthesis of secondary metabolites in A. nidulans. |