CMV-CcpA-mRuby2

Usage and Biology

The regulatory functions of CcpA are modulated by phosphorylation by serine/threonine kinases, which can affect its DNA-binding activity and thus its ability to regulate target genes. We aim to use this mechanism to detect ß-lactams, which can bind to pknB, potentially leading to phosphorylation of ccpA, which could then bind to a specifically engineered promoter. We therefore used an mRuby2 (K3338001)marker gene to detect localisation of ccpA protein in HEK292T cells.

Theoretical Part Design

Placing the ccpA (K3338014)upstream of the reporter gene mRuby2 (K3338001) allows for visualisation of location of ccpA.

Sequence and Features

Assembly Compatibility:

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COMPATIBLE WITH RFC[10]
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COMPATIBLE WITH RFC[12]
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COMPATIBLE WITH RFC[21]
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COMPATIBLE WITH RFC[23]
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COMPATIBLE WITH RFC[25]
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INCOMPATIBLE WITH RFC[1000]
Illegal SapI.rc site found at 1669

Cloning

We linearized the mammalian expression vector pEGFP-C2 with NheI and BamHI and inserted the both genes ccpA(K33380014) and mRuby2(K3338001), which were fused bevorhand together with matching overhangs. The ccpA gene was acquired from S. aureus. Following the NEBBuilder® user protocol this vector was cloned via HIFI assembly method.his composite part was cloned by using the primers in table 1.

HTML Table Caption Table1: Primers used to extract and clone the ccpA gene sequence.

Primer name	Sequence
ccpA_fw_1	tggatccccttttgtagttcctcggtattcaattctgtgag
ccpA_rv_2	TGAACCGTCAGATCCGatgacagttactatatatgatgtagcaagagaagc
ccpA_fw_3	actacaaaaggggatccaccggtcg
ccpA_rv_4	TCAGTTATCTAGATCCGGTGttacttgtacagctcgtccatcccacc

Characterisation

Transfection experiments in mammalian HEK293T cells assessed the promoter functionality, sensitivity and specifity. First, the composite part carrying plasmid was introduced via transfection to establish a baseline of endogenous promoter activity before performing co-transfection experiments with the CMV-ccpA-mRuby2 carrying plasmid (composite part K5317013) with ampicillin stimulation. The mRuby fluorescence signal was analyzed for localization by microscopy and intensity by FACS analysis.

Single-transfection experiments

Figure 2:

References

Bulock, L. L., Ahn, J., Shinde, D., Pandey, S., Sarmiento, C., Thomas, V. C., Guda, C., Bayles, K. W., & Sadykov, M. R. (2022). Interplay of CodY and CcpA in Regulating Central Metabolism and Biofilm Formation in Staphylococcus aureus. Journal of Bacteriology, 204(7), e00617-21. https://doi.org/10.1128/jb.00617-21

Liao, X., Li, H., Guo, Y., Yang, F., Chen, Y., He, X., Li, H., Xia, W., Mao, Z.-W., & Sun, H. (2022). Regulation of DNA-binding activity of the Staphylococcus aureus catabolite control protein A by copper (II)-mediated oxidation. Journal of Biological Chemistry, 298(3), 101587. https://doi.org/10.1016/j.jbc.2022.101587