Table 2.
Regulatory elements available for C. reinhardtii nuclear gene expression. Categorised based upon functional properties, promoters, regulatory elements, functional peptides, colorimetric reporters and highly expressed strains
| Functional element | Name | Phytozyme gene ID | Property | Reference |
|---|---|---|---|---|
| Promoters | HSP70A | Cre08.g372100 (196 bp upstream to ATG) | Typically used as constitutive; expression can be enhanced by high light and temperature | Schroda et al. (2000) |
| RBCS2 or HSP70A/RBCS2 | Cre02.g120150 (180 bp upstream to ATG) | Strong constitutive (refer to HSP70A) | Lumbreras et al. (1998) | |
| PSAD | Cre05.g238332 (822 bp upstream to ATG) | Typically employed as strong constitutive; expression maybe enhanced by high light | Fischer and Rochaix (2001) | |
| CYC6 | Cre16.g651050 (127 bp upstream to ATG) | Metal (Cu) responsive | Quinn and Merchant (1995) | |
| NIT1 | Cre09.g410950 (282 bp upstream to ATG) | Ammonium responsive | Ohresser et al. (1997) | |
| ATX1 | Cre09.g392467 (532 bp upstream to ATG) | Iron (Fe) responsive | Fei and Deng (2007) | |
| CA1 | Cre05.g248400 (194 bp upstream to ATG) | CO2 responsive | Villand et al. (1997) | |
| SQD2 | Cre01.g038550 (75 bp upstream to ATG) | Phosphate (P) responsive | Iwai et al. (2014) | |
| CAMV 35S | – | Enhancer and minimal promoter only | Ruecker et al. (2008) | |
| METE | Cre03.g180750 (–574 to –89 bp from ATG) | Cobalamin (B12) suppression | Helliwell et al. (2014) | |
| Regulatory elements | RBCS2 intron 1, 2 and 3 | Cre02.g120150 | Enhance gene expression as intron in coding region or 5′UTR | Eichler-Stahlberg et al. (2009), Lumbreras et al. (1998) |
| THI4 | Cre04.g214150 (1414 bp 5′UTR) | 5′UTR, thiamine (B1) suppression | Croft et al. (2007), Moulin et al. (2013) | |
| RBCS2 | 32 aa | Rubisco small subunit 2 chloroplast transit peptide | León et al. (2007) | |
| Functional peptides | FD | 32 aa | Ferredoxin chloroplast targeting transit peptide | León et al. (2007) |
| ARS2 | Cre16.g671350 (63 bp 5′ end from ATG) | N-terminal secretion | Eichler-Stahlberg et al. (2009) | |
| 2 x simian virus 40 (SV40) | 20 aa | N- terminal nuclear target peptide | Rasala and Mayfield (2014) | |
| Foot-and-mouth disease virus (FMDV) 2A | 20 aa | Translational cleavage peptide | Rasala et al. (2012) | |
| Gaussia luciferase (gLuc) | 555 bp | Luciferase assay | Ruecker et al. (2008) | |
| Reporter genes | GFP, mCHERRY, EYFP, DsRED, tdTOMATO, VENUS | 708–1437 bp | Fluorescent protein | Rasala et al. (2013) |
| ARS | Cre16.g671400 (3012 bp cDNA) | Chromogenic assay | Davies et al. (1992) | |
| Highly expressed host strains | UVM4 and UVM11 | – | High expression host, transgene silencing supressed | Neupert et al. (2009) |