Table 6 List of potential engineering targets for enhancing the synthesis of TAG and/or astaxanthin in C. zofingiensis
Gene Name | Gene ID | Function description | Expression pattern upon ND | Strategies |
|---|---|---|---|---|
Metabolic engineering for TAG improvements | ||||
PDHC | E1A (Cz03g08090), E1B (Cz01g37230) | Produces acetyl-CoA from pyruvate | Up-regulated | Overexpression |
ACS | ACS2 (Cz12g10100) | Produces acetyl-CoA from acetate | Up-regulated | Overexpression |
FAT | Cz04g05080 | Releases FFAs from acyl-ACPs | Up-regulated | Overexpression |
PGD1 | Cz01g38020 | Releases FFAs from MGDG | Up-regulated | Overexpression |
Putative membrane lipid lipases | Cz02g15090, Cz03g14190, Cz01g06170, Cz12g10010 | Releases FFAs from membrane lipids | Up-regulated | Overexpression |
LACS | LACS2 (Cz11g20120) | Converts FFAs to acyl-CoAs for TAG synthesis | Up-regulated | Overexpression |
GPDH | GPDH2 (Cz04g17090) | Converts DHAP to G3P for TAG synthesis | Up-regulated | Overexpression |
GK | GK2 (Cz18g13070) | Converts glycerol to G3P for TAG synthesis | Up-regulated | Overexpression |
GPAT | GPAT2 (Cz09g31330) | Transfers the acyl moiety from acyl-CoAs to G3P for LPA synthesis | Up-regulated | Overexpression |
LPAAT | LPAAT1 (Cz16g02090), LPAAT2 (Cz04g14150) | Transfers the acyl moiety from acyl-CoAs to LPA for PA synthesis | Up-regulated | Overexpression |
DGAT | DGAT1A (Cz06g05010), DGTT5 (Cz09g08290) | Transfers the acyl moiety from acyl-CoAs to DAG for TAG synthesis | Up-regulated | Overexpression |
MLDP | Cz04g29220 | Stabilizes LDs for TAG storage | Up-regulated | Overexpression |
Putative TAG lipases | SDP1 (Cz05g29160), Cz05g31060 | Hydrolysis of TAG | Down-regulated | Suppression |
LACS | LACS5 (Cz12g27140) | Converts FFAs to acyl-CoAs for β-oxidation | Little change | Suppression |
Metabolic engineering for astaxanthin improvements | ||||
DXS | Cz02g35280 | Involved in the MEP pathway for IPP/DMAPP | Little change | Overexpression |
DXR | Cz07g19130 | Involved in the MEP pathway for IPP/DMAPP | Little change | Overexpression |
HDR | Cz05g23010 | Involved in the MEP pathway for IPP/DMAPP | Little change | Overexpression |
PSY | Cz05g32220 | Condenses GGPP to phytoene | Little change | Overexpression |
PDS | Cz02g32280 | Converts phytoene to phytofluene | Little change | Overexpression |
LCYb | Cz12g10170 | Synthesizes β-carotene from lycopene | Up-regulated | Overexpression |
LCYe | Cz09g18310 | Synthesizes α-carotene from lycopene | Down-regulated | Suppression |
BKT | BKT1 (Cz13g13100) | Converts β-carotene and zeaxanthin to canthaxanthin and astaxanthin, respectively | Up-regulated | Overexpression |
CHYb | Cz12g16080 | Converts β-carotene to zeaxanthin | Up-regulated | Overexpression |
Metabolic engineering for both TAG and astaxanthin improvements | ||||
MYB | Cz10g24240, Cz06g23090 | MYB transcriptional factor predicted to regulate both TAG and astaxanthin synthesis | Up-regulated | Overexpression |
bHLH | Cz03g20070, UNPLg00160 | bHLH transcriptional factor predicted to regulate both TAG and astaxanthin synthesis | Up-regulated | Overexpression |
bZIP | Cz15g21170, UNPLg00449 | bZIP transcriptional factor predicted to regulate both TAG and astaxanthin synthesis | Up-regulated | Overexpression |
G6PD | Cz06g12080, Cz03g12030 | Provides NADPH | Up-regulated | Overexpression |
6PGD | Cz05g06160 | Provides NADPH | Up-regulated | Overexpression |
ME | Cz15g18140 | Produces pyruvate and NADPH from malate | Up-regulated | Overexpression |