Unraveling the Molecular Basis of Mycosporine Biosynthesis in Fungi
The <i>Phaffia rhodozyma</i> UCD 67-385 genome harbors a 7873 bp cluster containing <i>DDGS</i>, <i>OMT,</i> and <i>ATPG</i>, encoding 2-desmethy-4-deoxygadusol synthase, O-methyl transferase, and ATP-grasp ligase, respectively, of the mycosporine glut...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/6/5930 |
| Summary: | The <i>Phaffia rhodozyma</i> UCD 67-385 genome harbors a 7873 bp cluster containing <i>DDGS</i>, <i>OMT,</i> and <i>ATPG</i>, encoding 2-desmethy-4-deoxygadusol synthase, O-methyl transferase, and ATP-grasp ligase, respectively, of the mycosporine glutaminol (MG) biosynthesis pathway. Homozygous deletion mutants of the entire cluster, single-gene mutants, and the Δ<i>ddgs</i><sup>−/−</sup>;Δ<i>omt</i><sup>−/−</sup> and Δ<i>omt</i><sup>−/−</sup>;Δ<i>atpg</i><sup>−/−</sup> double-gene mutants did not produce mycosporines. However, Δ<i>atpg</i><sup>−/−</sup> accumulated the intermediate 4-deoxygadusol. Heterologous expression of the <i>DDGS</i> and <i>OMT</i> or <i>DDGS</i>, <i>OMT,</i> and <i>ATPG</i> cDNAs in <i>Saccharomyces cerevisiae</i> led to 4-deoxygadusol or MG production, respectively. Genetic integration of the complete cluster into the genome of the non-mycosporine-producing CBS 6938 wild-type strain resulted in a transgenic strain (CBS 6938_MYC) that produced MG and mycosporine glutaminol glucoside. These results indicate the function of <i>DDGS</i>, <i>OMT,</i> and <i>ATPG</i> in the mycosporine biosynthesis pathway. The transcription factor gene mutants Δ<i>mig1</i><sup>−/−</sup>, Δcyc8<sup>−/−</sup>, and Δ<i>opi1</i><sup>−/−</sup> showed upregulation, Δ<i>rox1</i><sup>−/−</sup> and Δ<i>skn7</i><sup>−/−</sup> showed downregulation, and Δ<i>tup6</i><sup>−/−</sup> and Δ<i>yap6</i><sup>−/−</sup> showed no effect on mycosporinogenesis in glucose-containing medium. Finally, comparative analysis of the cluster sequences in several <i>P. rhodozyma</i> strains and the four newly described species of the genus showed the phylogenetic relationship of the <i>P. rhodozyma</i> strains and their differentiation from the other species of the genus <i>Phaffia</i>. |
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| ISSN: | 1661-6596 1422-0067 |