Advanced Search
DSpace@MIT

Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein

Research and Teaching Output of the MIT Community

Show simple item record

dc.contributor.author Bertrand, Erin Marie
dc.contributor.author Allen, Andrew E.
dc.contributor.author Dupont, Christopher L.
dc.contributor.author Norden-Krichmar, Trina M.
dc.contributor.author Bai, Jing
dc.contributor.author Valas, Ruben E.
dc.contributor.author Saito, Mak A.
dc.date.accessioned 2012-11-15T19:52:03Z
dc.date.available 2012-11-15T19:52:03Z
dc.date.issued 2012-05
dc.date.submitted 2012-01
dc.identifier.issn 0027-8424
dc.identifier.issn 1091-6490
dc.identifier.uri http://hdl.handle.net/1721.1/74655
dc.description.abstract 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. en_US
dc.description.sponsorship National Science Foundation (U.S.) (Award ANT 0732665) en_US
dc.description.sponsorship National Science Foundation (U.S.) (Award OCE 0752291) en_US
dc.description.sponsorship National Science Foundation (U.S.) (Award OCE 1031271) en_US
dc.description.sponsorship National Science Foundation (U.S.). Graduate Research Fellowship Program (2007037200) en_US
dc.description.sponsorship United States. Environmental Protection Agency. Science to Achieve Results (STAR) (Fellowship F6E20324) en_US
dc.language.iso en_US
dc.publisher National Academy of Sciences en_US
dc.relation.isversionof http://dx.doi.org/10.1073/pnas.1201731109 en_US
dc.source PNAS en_US
dc.title Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein en_US
dc.type Article en_US
dc.identifier.citation 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
dc.contributor.mitauthor Bertrand, Erin Marie
dc.relation.journal Proceedings of the National Academy of Sciences en_US
dc.identifier.mitlicense PUBLISHER_POLICY en_US
dc.eprint.version Final published version en_US
dc.type.uri http://purl.org/eprint/type/JournalArticle en_US
eprint.status http://purl.org/eprint/status/PeerReviewed en_US
dspace.orderedauthors Bertrand, E. M.; Allen, A. E.; Dupont, C. L.; Norden-Krichmar, T. M.; Bai, J.; Valas, R. E.; Saito, M. A. en


Files in this item

Name Size Format
Downloadable Full Text - PDF

This item appears in the following Collection(s)

Show simple item record

Open Access