Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein
Diatoms are responsible for ∼40% of marine primary production and are key players in global carbon cycling. There is mounting evidence that diatom growth is influenced by cobalamin (vitamin B12) availability. This cobalt-containing micronutrient is only produced by some bacteria and archaea but is r...
| Những tác giả chính: | , , , , , , |
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| Định dạng: | Bài viết |
| Ngôn ngữ: | en_US |
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National Academy of Sciences
2012
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| Truy cập trực tuyến: | http://hdl.handle.net/1721.1/74655 |
| _version_ | 1826211814324568064 |
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| author | Bertrand, Erin Marie Allen, Andrew E. Dupont, Christopher L. Norden-Krichmar, Trina M. Bai, Jing Valas, Ruben E. Saito, Mak A. |
| author2 | Woods Hole Oceanographic Institution |
| author_facet | Woods Hole Oceanographic Institution Bertrand, Erin Marie Allen, Andrew E. Dupont, Christopher L. Norden-Krichmar, Trina M. Bai, Jing Valas, Ruben E. Saito, Mak A. |
| author_sort | Bertrand, Erin Marie |
| collection | MIT |
| description | Diatoms are responsible for ∼40% of marine primary production and are key players in global carbon cycling. There is mounting evidence that diatom growth is influenced by cobalamin (vitamin B12) availability. This cobalt-containing micronutrient is only produced by some bacteria and archaea but is required by many diatoms and other eukaryotic phytoplankton. Despite its potential importance, little is known about mechanisms of cobalamin acquisition in diatoms or the impact of cobalamin scarcity on diatom molecular physiology. Proteomic profiling and RNA-sequencing transcriptomic analysis of the cultured diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana revealed three distinct strategies used by diatoms to cope with low cobalamin: increased cobalamin acquisition machinery, decreased cobalamin demand, and management of reduced methionine synthase activity through changes in folate and S-adenosyl methionine metabolism. One previously uncharacterized protein, cobalamin acquisition protein 1 (CBA1), was up to 160-fold more abundant under low cobalamin availability in both diatoms. Autologous overexpression of CBA1 revealed association with the outside of the cell and likely endoplasmic reticulum localization. Cobalamin uptake rates were elevated in strains overexpressing CBA1, directly linking this protein to cobalamin acquisition. CBA1 is unlike characterized cobalamin acquisition proteins and is the only currently identified algal protein known to be implicated in cobalamin uptake. The abundance and widespread distribution of transcripts encoding CBA1 in environmental samples suggests that cobalamin is an important nutritional factor for phytoplankton. Future study of CBA1 and other molecular signatures of cobalamin scarcity identified here will yield insight into the evolution of cobalamin utilization and facilitate monitoring of cobalamin starvation in oceanic diatom communities. |
| first_indexed | 2024-09-23T15:11:49Z |
| format | Article |
| id | mit-1721.1/74655 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:11:49Z |
| publishDate | 2012 |
| publisher | National Academy of Sciences |
| record_format | dspace |
| spelling | mit-1721.1/746552024-06-28T13:49:05Z Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein Bertrand, Erin Marie Allen, Andrew E. Dupont, Christopher L. Norden-Krichmar, Trina M. Bai, Jing Valas, Ruben E. Saito, Mak A. Woods Hole Oceanographic Institution Bertrand, Erin Marie Diatoms are responsible for ∼40% of marine primary production and are key players in global carbon cycling. There is mounting evidence that diatom growth is influenced by cobalamin (vitamin B12) availability. This cobalt-containing micronutrient is only produced by some bacteria and archaea but is required by many diatoms and other eukaryotic phytoplankton. Despite its potential importance, little is known about mechanisms of cobalamin acquisition in diatoms or the impact of cobalamin scarcity on diatom molecular physiology. Proteomic profiling and RNA-sequencing transcriptomic analysis of the cultured diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana revealed three distinct strategies used by diatoms to cope with low cobalamin: increased cobalamin acquisition machinery, decreased cobalamin demand, and management of reduced methionine synthase activity through changes in folate and S-adenosyl methionine metabolism. One previously uncharacterized protein, cobalamin acquisition protein 1 (CBA1), was up to 160-fold more abundant under low cobalamin availability in both diatoms. Autologous overexpression of CBA1 revealed association with the outside of the cell and likely endoplasmic reticulum localization. Cobalamin uptake rates were elevated in strains overexpressing CBA1, directly linking this protein to cobalamin acquisition. CBA1 is unlike characterized cobalamin acquisition proteins and is the only currently identified algal protein known to be implicated in cobalamin uptake. The abundance and widespread distribution of transcripts encoding CBA1 in environmental samples suggests that cobalamin is an important nutritional factor for phytoplankton. Future study of CBA1 and other molecular signatures of cobalamin scarcity identified here will yield insight into the evolution of cobalamin utilization and facilitate monitoring of cobalamin starvation in oceanic diatom communities. National Science Foundation (U.S.) (Award ANT 0732665) National Science Foundation (U.S.) (Award OCE 0752291) National Science Foundation (U.S.) (Award OCE 1031271) National Science Foundation (U.S.). Graduate Research Fellowship Program (2007037200) United States. Environmental Protection Agency. Science to Achieve Results (STAR) (Fellowship F6E20324) 2012-11-15T19:52:03Z 2012-11-15T19:52:03Z 2012-05 2012-01 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/74655 Bertrand, E. M. et al. “Influence of Cobalamin Scarcity on Diatom Molecular Physiology and Identification of a Cobalamin Acquisition Protein.” Proceedings of the National Academy of Sciences 109.26 (2012): E1762–E1771. ©2012 by the National Academy of Sciences en_US http://dx.doi.org/10.1073/pnas.1201731109 Proceedings of the National Academy of Sciences application/pdf National Academy of Sciences PNAS |
| spellingShingle | Bertrand, Erin Marie Allen, Andrew E. Dupont, Christopher L. Norden-Krichmar, Trina M. Bai, Jing Valas, Ruben E. Saito, Mak A. Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title | Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title_full | Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title_fullStr | Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title_full_unstemmed | Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title_short | Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| title_sort | influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein |
| url | http://hdl.handle.net/1721.1/74655 |
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