Modifying the yeast very long chain fatty acid biosynthetic machinery by the expression of plant 3-ketoacyl CoA synthase isozymes

Abstract

Eukaryotes express a multi-component fatty acid elongase to produce very long chain fatty acids (VLCFAs), which are building blocks of diverse lipids. Elongation is achieved by cyclical iteration of four reactions, the first of which generates a new carbon-carbon bond, elongating the acyl-chain. This reaction is catalyzed by either ELONGATION DEFECTIVE LIKE (ELO) or 3-ketoacyl-CoA synthase (KCS) enzymes. Whereas plants express both ELO and KCS enzymes, other eukaryotes express only ELOs. We explored the KCS and ELO enzymatic redundancies by expressing the former in yeast strains that lacked endogenous ELO isozymes. Expression of the 26 maize KCS isozymes in wild-type, scelo2 or scelo3 single mutants did not affect VLCFA profiles. However, five of these KCSs were capable of complementing the lethal scelo2; scelo3 double mutant. These rescued strains express novel VLCFA profiles reflecting the different catalytic capabilities of the KCS isozymes. These novel strains offer a platform to explore the relationship between VLCFA profiles and cellular physiology.

Genetic dissection of QTLs for oil content in four maize DH populations

“…Five KCS genes encoding bketoacyl CoA synthase isozymes in qOC-1-3, qOC-2-1, qOC-3-4 and qOC-4-4 are mainly involved in the process of elongation of the C16:0-and C18:0-CoAs into very-long-chain fatty acids (VLCFAs) (Gonzales-Vigil et al, 2017). The maize isozymes reflected differences in the enzymatic capability to elongate fatty acids (Stenback et al, 2022). The FAD genes in qOC-1-3 and qOC-2-2 were identified as fatty acid desaturase-coding and are responsible for the production of trienoic fatty acids by unsaturation at the w-3 position and the cDNAs corresponding to the loci have been isolated (Ohlrogge and Browse, 1995;Gao et al, 2015;Zhao et al, 2019).…”

Genome-wide identification and expression analysis of 3-ketoacyl-CoA synthase gene family in rice (Oryza sativa L.) under cadmium stress

“…There are two types of non-homologous condensing enzymes involved in fatty acid elongation in organisms: one of these is FAE1like 3-ketoacyl-CoA synthases (KCS-type enzymes), and the other is ELONGATION DEFECTIVE-LIKE proteins (ELO-LIKEs). ELO-LIKEs are found in many organisms such as humans, plants, and yeasts, whereas KCSs are only found in plants and protists (Stenback et al, 2022). Several studies have been performed on the KCS gene family in plants.…”

Single-cell genetic models to evaluate orphan gene function: The case of QQS regulating carbon and nitrogen allocation

“…The yeast strains that have been developed herein can be used as platforms to explore the role of the functionality of the large number of NF-YA, NF-YB and NF-YC Arabidopsis paralogs in affecting C and N allocation in the context of the QQS orphan gene. Using synthetic biological technologies that have been widely utilized to reconstitute biological processes, for example, human metabolic pathways (Carreras et al, 1997;Hopwood, 1997;Staunton and Weissman, 2001) or plant lipid metabolic pathways (Campbell et al, 2019;Stenback et al, 2022), one can readily envision strategies that systematically replace individual NF-YA, NF-YB and NF-YC Arabidopsis paralogs into the strains expressing QQS, and thereby individually evaluate how these different combinations of NF-Y subunits can affect the C and N allocation phenotypes. For example, such synthetic biology strategies would provide experimental evidence to support the "mimicry-model" for orphan gene function, generated from the experiments that have provided a mechanistic understanding of QQS function, which impacts a variety of different phenotypes.…”