GeneArt™ Chlamydomonas Protein Expression Vector

The pChlamy_4 vector was designed in order to circumvent the transgene silencing that often occurs in C. reinhardtii. This vector is also designed so that proteins are expressed as transcriptional fusions with the blemoycin/zeocin resistance gene (sh-ble). The self-cleaving sequence for the 2A peptide from the foot-and-mouth-disease-virus (FMDV) is placed between the antibiotic resistance gene and the gene of interest. It encodes a short ~20 amino acid sequence that mediates proper cleavage to yield two discrete proteins. With this system we have seen positive transformants maintain high expression levels for much longer than with other systems, even after many passages with or without selection pressure.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

Yes. For the TOPO version, you can design the primer to make sure the coding sequence is in frame with the ATG in the vector.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

The expected time constant is 15-20 milliseconds (average is 17 milliseconds).

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

We don't report transformation efficiency of the Chlamydomonas cells, since the end result of transformation is random integration into the genome. The electroporation results will depend on the gene of interest. The control vector should produce a minimum of 30 transformants per electroporation reaction. Approximately 90% of colonies picked should be positive clones containing your gene of interest.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

Integration is at random. The engineering kit is based on a random insertion in which the gene of interest can be lost very quickly. For the protein expression kit, the pChlamy_4 vector is designed so proteins are expressed as transcriptional fusions with the bleomycin/zeocin resistance gene sh-ble (Rasala et al., 2012). The self-cleaving sequence for the 2A peptide from the foot-and-mouth disease virus (FMDV) is placed between the antibiotic resistance gene and the gene of interest. It encodes a short ˜20 amino acid sequence that mediates proper cleavage to yield two discrete proteins. With this system we have seen positive transformants maintain high expression levels for much longer than with other systems, even after many passages with or without selection pressure.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.