A Toolkit for Rapid Modular Construction of Biological Circuits in Mammalian Cells

João Pedro Fonseca; Alain R. Bonny; G. Renuka Kumar; Andrew H. Ng; Jason Town; Qiu Chang Wu; Elham Aslankoohi; Susan Y. Chen; Patrick Harrigan; Lindsey C. Osimiri; Amy L. Kistler; Hana El-Samad

Moreover, replacing a canonical 3' UTR sequence with either of the spacer sequences diminishes expression of its upstream coding sequence, but the spacers still enable appreciable expression over background. The two spacers differ in their use: including a stop codon allows for efficient reverse-transcription in lentiviral preparation while omitting the stop codon enables read-through in multicistronic plasmids. Finally, the MTK contains two inducible promoters whose use is illustrated in Fig. 6 . This characterized suite of constitutive promoters and 3' UTR's coupled with the facile assembly can generate libraries of fine-tuned expression of a protein of interest. We only explored here a few combinations related to one promoter (EF1a), but other combinations can be easily assembled using the parts already provided in the MTK and assayed by the interested user.