Difference between revisions of "Part:BBa K782013"
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TALB label represents TAL effector 1297 from zebrafish experiments (Sander et al., 2011). | TALB label represents TAL effector 1297 from zebrafish experiments (Sander et al., 2011). | ||
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==Introduction== | ==Introduction== | ||
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TAL effectors (TALEs) are bacterial plant pathogen transcription factors, that bind to DNA by specifically recognizing one base pair with a single tandem repeat in their DNA-binding domain. A tandem TALE repeat contains 33 to 35 amino acids, where the 12th and 13th amino acid, called a “repeat variable diresidue” (RVD), are responsible for specific interactions with the corresponding base pair (Scholze and Boch, 2011). | TAL effectors (TALEs) are bacterial plant pathogen transcription factors, that bind to DNA by specifically recognizing one base pair with a single tandem repeat in their DNA-binding domain. A tandem TALE repeat contains 33 to 35 amino acids, where the 12th and 13th amino acid, called a “repeat variable diresidue” (RVD), are responsible for specific interactions with the corresponding base pair (Scholze and Boch, 2011). | ||
| − | VP16 is a 490-amino-acid protein that contains a core domain, which is enriched in acidic residues. The VP16 core contains both structured and unstructured regions. The structured region possesses a seat-like structure in which the seat surface recognizes and binds the TAATGARAT. On its own, however, VP16 does not bind to DNA well. Instead, VP16 is stabilized on the DNA by the unstructured region which interacts with Oct-1, HCF-1 and the DNA in the complex. In this complex, VP16 is able to activate transcription (Wysocka et al., 2003) | + | VP16 is a 490-amino-acid protein that contains a core domain, which is enriched in acidic residues. The VP16 core contains both structured and unstructured regions. The structured region possesses a seat-like structure in which the seat surface recognizes and binds the TAATGARAT. On its own, however, VP16 does not bind to DNA well. Instead, VP16 is stabilized on the DNA by the unstructured region which interacts with Oct-1, HCF-1 and the DNA in the complex. In this complex, VP16 is able to activate transcription (Wysocka et al., 2003). |
We designed TALE-based activators for specific gene activation, by fusing TAL effectors with the VP16 activator domain downstream of the minimal promoter. VP16 was placed on the C-terminal ends of the TALE DNA-binding domain (Figure 1). | We designed TALE-based activators for specific gene activation, by fusing TAL effectors with the VP16 activator domain downstream of the minimal promoter. VP16 was placed on the C-terminal ends of the TALE DNA-binding domain (Figure 1). | ||
| − | [[Image: | + | [[Image:Svn_12_TALaktivatorB--.png]] |
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| + | '''Figure 1:''' Schematic representation of the activator construct. | ||
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| + | Single binding sequence for TALB: tCTTCCGTTTCCACATCT | ||
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==Characterization== | ==Characterization== | ||
| − | HEK293T cells were cotransfected with TAL activator | + | HEK293T cells were cotransfected with TAL activator construct, constituitively expressed by the CMV promoter, and mCitrine [https://parts.igem.org/wiki/index.php?title=Part:BBa_K782030 reporter plasmid], containing 10 binding sites for the designated TAL activator upstream of a minimal promoter (Figure 2). All experiments were executed in 3 biological replicates and repeated over 3 times with similar results. Tested TAL activator exhibited over 1500-fold activation of the mCitrine reporter (Figure 3). |
[[Image:Svn_12_PMIN_sistem.png | 300 px]] | [[Image:Svn_12_PMIN_sistem.png | 300 px]] | ||
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'''Figure 2:''' Schematic representation of activation experiments. A: in the absence of a TAL activator, the expression of the reporter gene is repressed. B: when TAL activator is present, it binds to its respective binding site upstream of the minimal promoter and activates transcription of the reporter gene with the VP16 domain. | '''Figure 2:''' Schematic representation of activation experiments. A: in the absence of a TAL activator, the expression of the reporter gene is repressed. B: when TAL activator is present, it binds to its respective binding site upstream of the minimal promoter and activates transcription of the reporter gene with the VP16 domain. | ||
| − | [[Image: | + | [[Image:Svn_12_TALB-VP16-graf_.png | 300 px]] |
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| + | '''Figure 3:''' Testing activation of reporter gene ([https://parts.igem.org/wiki/index.php?title=Part:BBa_K782030 BBa_K782030]) transcription by addition of TALB:NLS:VP16 activator. | ||
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*VP16 domain was contributed by the host lab | *VP16 domain was contributed by the host lab | ||
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==References== | ==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 | + | 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 | + | Scholze, H., and Boch, J. (2011) TAL effectors are remote controls for gene activation. Curr. Opin. Microbiol. 14, 47-53. |
| − | Wysocka J. and Herr W (2003) The herpes simplex virus VP16-induced complex: the makings of a regulatory switch. TRENDS in Biochemical Sciences 28, 294-304 | + | Wysocka J. and Herr W (2003) The herpes simplex virus VP16-induced complex: the makings of a regulatory switch. TRENDS in Biochemical Sciences 28, 294-304. |
Latest revision as of 21:24, 26 September 2012
TALB:NLS:VP16
TALB label represents TAL effector 1297 from zebrafish experiments (Sander et al., 2011).
Introduction
TAL effectors (TALEs) are bacterial plant pathogen transcription factors, that bind to DNA by specifically recognizing one base pair with a single tandem repeat in their DNA-binding domain. A tandem TALE repeat contains 33 to 35 amino acids, where the 12th and 13th amino acid, called a “repeat variable diresidue” (RVD), are responsible for specific interactions with the corresponding base pair (Scholze and Boch, 2011).
VP16 is a 490-amino-acid protein that contains a core domain, which is enriched in acidic residues. The VP16 core contains both structured and unstructured regions. The structured region possesses a seat-like structure in which the seat surface recognizes and binds the TAATGARAT. On its own, however, VP16 does not bind to DNA well. Instead, VP16 is stabilized on the DNA by the unstructured region which interacts with Oct-1, HCF-1 and the DNA in the complex. In this complex, VP16 is able to activate transcription (Wysocka et al., 2003).
We designed TALE-based activators for specific gene activation, by fusing TAL effectors with the VP16 activator domain downstream of the minimal promoter. VP16 was placed on the C-terminal ends of the TALE DNA-binding domain (Figure 1).
Figure 1: Schematic representation of the activator construct.
Single binding sequence for TALB: tCTTCCGTTTCCACATCT
Characterization
HEK293T cells were cotransfected with TAL activator construct, constituitively expressed by the CMV promoter, and mCitrine reporter plasmid, containing 10 binding sites for the designated TAL activator upstream of a minimal promoter (Figure 2). All experiments were executed in 3 biological replicates and repeated over 3 times with similar results. Tested TAL activator exhibited over 1500-fold activation of the mCitrine reporter (Figure 3).
Figure 2: Schematic representation of activation experiments. A: in the absence of a TAL activator, the expression of the reporter gene is repressed. B: when TAL activator is present, it binds to its respective binding site upstream of the minimal promoter and activates transcription of the reporter gene with the VP16 domain.
Figure 3: Testing activation of reporter gene (BBa_K782030) transcription by addition of TALB:NLS:VP16 activator.
- VP16 domain was contributed by the host lab
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.
Wysocka J. and Herr W (2003) The herpes simplex virus VP16-induced complex: the makings of a regulatory switch. TRENDS in Biochemical Sciences 28, 294-304.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BamHI site found at 2439
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]