Complex Ancestries of Isoprenoid Synthesis in Dinoflagellates.
Isoprenoid metabolism occupies a central position in the anabolic metabolism of all living cells. In plastid-bearing organisms, two pathways may be present for de novo isoprenoid synthesis, the cytosolic mevalonate pathway (MVA) and nuclear-encoded, plastid-targeted nonmevalonate pathway (DOXP). Using transcriptomic data we find that dinoflagellates apparently make exclusive use of the DOXP pathway. Using phylogenetic analyses of all DOXP genes we inferred the evolutionary origins of DOXP genes in dinoflagellates. Plastid replacements led to a DOXP pathway of multiple evolutionary origins. Dinoflagellates commonly referred to as dinotoms due to their relatively recent acquisition of a diatom plastid, express two completely redundant DOXP pathways. Dinoflagellates with a tertiary plastid of haptophyte origin, by contrast, express a hybrid pathway of dual evolutionary origin. Here, changes in the targeting motif of signal/transit peptide likely allow for targeting the new plastid by the proteins of core isoprenoid metabolism proteins. Parasitic dinoflagellates of the Amoebophyra species complex appear to have lost the DOXP pathway, suggesting that they may rely on their host for sterol synthesis.
CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742.
Bastian
B
Bentlage
CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742.
Travis S
TS
Rogers
Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E Pratt St., Baltimore, Maryland, 21202.
Tsvetan R
TR
Bachvaroff
CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742.|Maryland Agricultural Experiment Station, AGNR, University of Maryland, College Park, Maryland, 20742.
Charles F
CF
Delwiche
D004141:Dinoflagellida / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008798:Mevalonic Acid / Q000378:metabolism; D010802:Phylogeny; D018087:Plastids; D013261:Sterols / Q000096:biosynthesis; D013729:Terpenes / Q000378:metabolism*
D013261:Sterols; D013729:Terpenes; D008798:Mevalonic Acid
DOXP; Dinoflagellata; Haptophyta; MEP; MVA; endosymbiont gene transfer; mevalonate