Polyketide biosynthesis in dinoflagellates: what makes it different?

Abstract

Dinoflagellates produce unique polyketides characterized by their size and complexity. The biosynthesis of a limited number of such metabolites has been reported, with studies largely hampered by the low yield of compounds and the severe scrambling of label in the isotopically-labeled precursors. Nonetheless, of the successful biosynthetic experiments that have been reported, many surprising and unique processes have been discovered. This knowledge has been accessed through a series of biochemical labeling studies, and while limited molecular genetic data has been amassed, it is still in the early stages of development. In an attempt to meet this challenge, this review has compared some of the biosynthetic processes with similar ones identified in other microbes such as bacteria and myxobacteria, with the idea that similar genes and enzymes are employed by dinoflagellates.

Transcriptome Analysis of Core Dinoflagellates Reveals a Universal Bias towards “GC” Rich Codons

“…The global nature of this phenomenon to control gene expression gives codon bias the potential to explain the enigmatic reliance on post-transcriptional control of gene expression in dinoflagellates. Toxins made by dinoflagellates can be large complex structures and are likely produced by polyketide synthases and/or non-ribosomal protein synthases that are subsequently modified to their final form [26,27,28]. Toxin production, release, and modification can be correlated to a host of genotypic and environmental factors, implying a complex regulatory network.…”

Characterization of Acetyl-CoA Carboxylases in the Basal Dinoflagellate Amphidinium carterae

“…Due to the high peptide coverage (Figure 4) and high expression level (fragments per kilobase per million mapped reads) (Figure 1), these proteins are abundantly expressed and translated in the cell [25]. These proteins are present in large amounts likely because they catalyze a limiting step in essential fatty acid synthesis and the production of secondary metabolites through polyketide synthases [29]. These proteins now represent an attractive target for further dissection of the PKS/FAS pathways in dinoflagellates.…”

Biosynthetic Study of Amphidinin A and Amphidinolide P

“…The direct experimental evidence has not been found yet, however, the incorporation patterns obtained from many feeding experiments indicated the possible involvement of the 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (HCS) cassette to the addition of this kind of branched C 1 unit. 8,24) Though the mechanism of unusual dinoflagellate polyketide chain extension was unknown, C 1 unit come from C-2 of cleaved acetate in polyketide chain might exist as carbonyl carbon at the early stage. In fact, almost all C 1 units originated from * To whom correspondence should be addressed.…”

“…[2][3][4][5][6][7] The carbon skeletons of dinoflagellate polyketides are unique and unavailable from other organisms, since they might be generated by unexplained one-carbon extension machinery in addition to the ordinary polyketide biosynthesis. 8) In our continuing biosynthetic study of dinoflagellate polyketides, [9][10][11][12][13][14][15][16] we have recently re-isolated amphidinin A (1) 17,18) and amphidinolide P (2) 19,20) from the cultured marine dinoflagellate Amphidinium sp. (2012-7-4A strain) which were isolated from an acoel flatworm Amphiscolops sp.…”