Journal
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
Volume 65, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.algal.2022.102728
Keywords
Fucoxanthin; Genetic engineering; Neoxanthin; Phaeodactylum tricornutum
Categories
Funding
- National Key Research and Development Program of China [2018YFD0900703]
- National Natural Science Foundation of China [31902370, U1706212, 41976118]
Ask authors/readers for more resources
This study investigated the function of a protein called PtABA4 in the synthesis of fucoxanthin, a valuable carotenoid. The overexpression and knockdown of PtABA4 in Phaeodactylum tricornutum showed significant changes in fucoxanthin accumulation. It is speculated that PtABA4 may form multi-enzyme complexes with other membrane associated enzymes and participate in the formation of various carotenoids.
Although fucoxanthin is one of the most valuable carotenoids, its biosynthesis pathway is still poorly understood. Neoxanthin has been regarded as the intermediate of fucoxanthin in recent years, however, multiple details still need to be explored. Previous study performed in Arabidopsis thaliana demonstrated a DUF4281-domain containing protein (ABA4) was necessary for the biosynthesis of neoxanthin, and the mutation of ABA4 led to a huge alteration of pigment composition. In Phaeodactylum tricornutum, a function unknown protein (designated as PtABA4 in this study) displayed high homology to ABA4, and also contained DUF4281 domain. To investigate its function on neoxanthin synthesis and fucoxanthin accumulation, we conducted endogenous overexpression and knockdown (RNA interference) of PtABA4 individually, as well as in vitro activity assay using recombinant protein. The overexpression and knockdown of PtABA4 lead to sharp increases and decrease of fucoxanthin, respectively, demonstrating a key role of PtABA4 on fucoxanthin accumulation. Unexpectedly, the knockdown of PtABA4 results in the decreases of upstream carotenoids of neoxanthin, rather than compensatory increases. In terms of in vitro activity assay, neither the recombinant protein produced by Escherichia coli nor the overexpressed transformant displays neoxanthin synthase activity. Taking all results into consideration, we speculate that the PtABA4 may constitute one multienzyme complexes with other membrane associated enzymes and participate in the formation of several carotenoids, rather than neoxanthin only. The ubiquity of DUF4281 domain across all taxa and the absence of xanthophylls in bacteria provide indirect evidence for our assumption. Above all, this study here provides a target gene for enhancing the fucoxanthin content by genetic engineering methods, and deeps the understanding about the function of DUF4281 domain.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available