Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i>
Dinoflagellates are unicellular organisms that are implicated in harmful algal blooms (HABs) caused by potent toxins that are produced through polyketide synthase (PKS) pathways. However, the exact mechanisms of toxin synthesis are unknown due to a lack of genomic segregation of fat, toxins, and oth...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-07-01
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| Series: | Marine Drugs |
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| Online Access: | https://www.mdpi.com/1660-3397/21/8/425 |
| _version_ | 1797584046532853760 |
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| author | Saddef Haq Benjamin L. Oyler Ernest Williams Mohd M. Khan David R. Goodlett Tsvetan Bachvaroff Allen R. Place |
| author_facet | Saddef Haq Benjamin L. Oyler Ernest Williams Mohd M. Khan David R. Goodlett Tsvetan Bachvaroff Allen R. Place |
| author_sort | Saddef Haq |
| collection | DOAJ |
| description | Dinoflagellates are unicellular organisms that are implicated in harmful algal blooms (HABs) caused by potent toxins that are produced through polyketide synthase (PKS) pathways. However, the exact mechanisms of toxin synthesis are unknown due to a lack of genomic segregation of fat, toxins, and other PKS-based pathways. To better understand the underlying mechanisms, the actions and expression of the PKS proteins were investigated using the toxic dinoflagellate <i>Amphidinium carterae</i> as a model. Cerulenin, a known ketosynthase inhibitor, was shown to reduce acetate incorporation into all fat classes with the toxins amphidinol and sulpho-amphidinol. The mass spectrometry analysis of cerulenin-reacted synthetic peptides derived from ketosynthase domains of <i>A. carterae</i> multimodular PKS transcripts demonstrated a strong covalent bond that could be localized using collision-induced dissociation. One multi-modular PKS sequence present in all dinoflagellates surveyed to date was found to lack an AT domain in toxin-producing species, indicating <i>trans</i>-acting domains, and was shown by Western blotting to be post-transcriptionally processed. These results demonstrate how toxin synthesis in dinoflagellates can be differentiated from fat synthesis despite common underlying pathway. |
| first_indexed | 2024-03-10T23:47:43Z |
| format | Article |
| id | doaj.art-9412fc2c1c8d43f1a6e9e0c285f4ddc4 |
| institution | Directory Open Access Journal |
| issn | 1660-3397 |
| language | English |
| last_indexed | 2024-03-10T23:47:43Z |
| publishDate | 2023-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Marine Drugs |
| spelling | doaj.art-9412fc2c1c8d43f1a6e9e0c285f4ddc42023-11-19T01:57:50ZengMDPI AGMarine Drugs1660-33972023-07-0121842510.3390/md21080425Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i>Saddef Haq0Benjamin L. Oyler1Ernest Williams2Mohd M. Khan3David R. Goodlett4Tsvetan Bachvaroff5Allen R. Place6Institute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USAUniversity of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USAInstitute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USAUniversity of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USADepartment of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8S 1P7, CanadaInstitute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USAInstitute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USADinoflagellates are unicellular organisms that are implicated in harmful algal blooms (HABs) caused by potent toxins that are produced through polyketide synthase (PKS) pathways. However, the exact mechanisms of toxin synthesis are unknown due to a lack of genomic segregation of fat, toxins, and other PKS-based pathways. To better understand the underlying mechanisms, the actions and expression of the PKS proteins were investigated using the toxic dinoflagellate <i>Amphidinium carterae</i> as a model. Cerulenin, a known ketosynthase inhibitor, was shown to reduce acetate incorporation into all fat classes with the toxins amphidinol and sulpho-amphidinol. The mass spectrometry analysis of cerulenin-reacted synthetic peptides derived from ketosynthase domains of <i>A. carterae</i> multimodular PKS transcripts demonstrated a strong covalent bond that could be localized using collision-induced dissociation. One multi-modular PKS sequence present in all dinoflagellates surveyed to date was found to lack an AT domain in toxin-producing species, indicating <i>trans</i>-acting domains, and was shown by Western blotting to be post-transcriptionally processed. These results demonstrate how toxin synthesis in dinoflagellates can be differentiated from fat synthesis despite common underlying pathway.https://www.mdpi.com/1660-3397/21/8/425dinoflagellatePKScerulenintoxin |
| spellingShingle | Saddef Haq Benjamin L. Oyler Ernest Williams Mohd M. Khan David R. Goodlett Tsvetan Bachvaroff Allen R. Place Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> Marine Drugs dinoflagellate PKS cerulenin toxin |
| title | Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> |
| title_full | Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> |
| title_fullStr | Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> |
| title_full_unstemmed | Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> |
| title_short | Investigating A Multi-Domain Polyketide Synthase in <i>Amphidinium carterae</i> |
| title_sort | investigating a multi domain polyketide synthase in i amphidinium carterae i |
| topic | dinoflagellate PKS cerulenin toxin |
| url | https://www.mdpi.com/1660-3397/21/8/425 |
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