Difference between revisions of "Part:BBa K782019"

Revision as of 19:53, 26 September 2012

10x[TALA+TALB] operator_CMV promoter_fLuciferase

• TALA and TALB labels represents TAL effectors 1257 and 1297 respectively from zebrafish experiments (Sander et al., 2011)
• DNA binding sites for individual TAL effectors are indicated with square brackets [ ]

Introduction

Transcription activation like (TAL) effectors are DNA binding proteins with a high specifity, built from tandem repeats, with near identical seqences, differing only in two amino acids in each repeat called “repeat variable diresidue” (RVD), which determine the specifity for a single nucleotide.(Scholze and Boch, 2011)

We designed our construct with 10 alterations of binding sites for TALA and TALB, upstream of a CMV promoter (constitutive promoter for expression in mammalian cells). Downstream of the promoter we cloned fLuciferase (firefly luciferase) to function as a reporter.

Figure1:Schematic representation of our construct

Characterisation

HEK293T cells were transfected with the 10x[TALA+TALB] operator_CMV promoter_fLuciferase reporter and TALA:NLS:KRAB or TALB:NLS:KRAB (Figure 2). Test showed successful repression with either TAL repressor (Figure 3).

Figure 2:Schematic representation of repression experiments. A: in the absence of a TAL repressor, the reporter gene is constituitively expressed. B: when a TALA:NLS:KRAB is present, it binds to its binding site upstream of the CMV promoter and represses transcription of fLuciferase with the KRAB domain.

Figure 3: Repression of luciferase reporter. Control: 10x[TALA+TALB] operator_CMV promoter_fLuciferase without TAL:NLS:KRAB

• fLuciferase was contributed by host lab
• Binding sites for TAL effectors were ordered from GeneArt.

References

Sander, J. D., Cade, L., Khayter, C., Reyon, D., Peterson, R. T., Joung, J. K., and Yeh, J.-R. J. (2011) Targeted gene disruption in somatic zebrafish cells using engineered TALENs. Nature Biotechnology 29, 697–698

Scholze, H., and Boch, J. (2011) TAL effectors are remote controls for gene activation. Curr. Opin. Microbiol. 14, 47-53

Sequence and Features