Difference between revisions of "Part:BBa K2632003"
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− | Pyroptosis is a form of lytic programmed cell death with inflammation. Recent studies reported that the N-terminal of | + | Pyroptosis is a form of lytic programmed cell death with inflammation. Recent studies reported that the N-terminal of GSDMD acts as an effector of pyroptosis. Full length GSDMD (GSDMD FL) is cleaved by Caspase 1, releasing the pore-forming domain (GSDMD-N275) which can oligomerize and make pores on the cell membrane. Formation of pores causes cell to swell, leading to membrane rupture and massive leakage of cytosolic contents<sup>1</sup>. |
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− | The N-terminal of GSDMD | + | <h2>The N-terminal of GSDMD performs the function of pyroptosis in cells</h2> |
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− | We | + | We fused eGFP with GSDMD-N275 and GSDMD FL (full length), respectively. Then the corresponding plasmids were transfected into Hela GSDMD KO (knockout) cell. Cell microscopy showed that the cells transfected with GSDMD-N275 underwent pyroptosis while the cells with GSDMD FL did not (<b>Figure 1</b>). We also tested the cell viability though an ATP assay (CellTiter-Glo<sup>®</sup> Luminescent Cell Viability Assay) and demonstrated that GSDMD-N275 and mutants of GSDMD FL have different ability to induce pyroptosis (<b>Figure 2</b>). |
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− | <img src="https://static.igem.org/mediawiki/ | + | <div style="width: 100%; margin: 30px auto"> |
+ | <img src="https://static.igem.org/mediawiki/2018/d/d7/T--HZAU-China--basicPart1.png.png" width="100%" alt=""> | ||
+ | </div> | ||
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− | Figure 1. pCS2-eGFP-GSDMD | + | <b>Figure 1.</b> Microscopy of the Hela GSDMD KO cells transfected with pCS2-eGFP-GSDMD FL and pCS2-eGFP-GSDMD-N275, respectively. Pyroptotic cells are pointed by red arrow. |
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− | <img src="https://static.igem.org/mediawiki/2018/ | + | <div style="width: 50%; margin: 30px auto"> |
+ | <img src="https://static.igem.org/mediawiki/2018/f/f5/T--HZAU-China--basicPart2.png" width="100%" alt=""> | ||
+ | </div> | ||
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− | Figure 2. pCS2-Flag-GSDMD FL, pCS2-Flag-GSDMD-N275, pCS2-Flag-GSDMD L290D, pCS2-Flag-GSDMD | + | <b>Figure 2.</b> Cell viability of the 293T cells transfected with pCS2-Flag-GSDMD FL, pCS2-Flag-GSDMD-N275, pCS2-Flag-GSDMD L290D, pCS2-Flag-GSDMD Y373D, pCS2-Flag-GSDMD A377D, respectively. Asterisks indicate the statistically significant differences. ATP-based cell viability was measured (n=6).</p> |
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− | The N-terminal of GSDMD lyses bacteria | + | <h2>The N-terminal of GSDMD lyses bacteria</h2> |
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− | Expression of the N terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) | + | Expression of the N terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) in <i>Salmonella enterica</i> serovar Typhimurium str. SL1344 <i>ΔsifA</i> |
+ | is under the control of Ptet. The colony-forming unit (CFU) was measured for counting the number of viable bacteria (<b>Figure 3</b>). | ||
+ | The result shows that eGFP-GSDMD-N275 exhibits cytotoxicity to bacteria. | ||
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− | <img src="https://static.igem.org/mediawiki/ | + | <div style="width: 30%; margin: 30px auto"> |
+ | <img src="https://static.igem.org/mediawiki/2018/f/fb/T--HZAU-China--basicPart3.jpg" width="100%" alt=""> | ||
+ | </div> | ||
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− | In each group, ATc ( | + | <b>Figure 3.</b> CFU comparison between the SL1344 <i>ΔsifA</i> cells with eGFP-GSDMD-N275 plasmid and with the empty vector. |
+ | In each group, ATc (15μg/ml) was added into medium when bacteria grew to logarithmic phase (OD = 0.6~0.8). | ||
+ | Vector refers to bacteria containing a high copy number plasmid which only expresses TetR under the control of P<sub>tet</sub> . | ||
+ | Bacterial colony-forming units (CFU) for vector and eGFP-GSDMD-N275 are shown in the logarithmic form (log10) (n = 3). | ||
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− | The N-terminal of GSDMD from lytic bacteria | + | <h2>The N-terminal of GSDMD from lytic bacteria induces cell pyroptosis</h2> |
− | Expression of the N-terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) is under the control of tet promoter in <i>ΔsifA</i> SL1344. Hela GSDMD KO | + | <br> |
+ | Expression of the N-terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) is under the control of tet promoter in <i>ΔsifA</i> SL1344. | ||
+ | Hela GSDMD KO cells were infected with <i>ΔsifA</i> SL1344. Inducer ATc (16μg/mL) was added 3h after infection. | ||
+ | Microscopy shows that eGFP-GSDMD-N275 locates in cytoplasm after 5 min of induction and triggers pyroptosis after 30 min of induction (<b>Figure 4</b>). | ||
+ | By counting the population of ruptured cells, there is a 1.96 fold-change between the induced group and the control group (<b>Figure 5</b>). | ||
+ | So the pyroptosis of host cell in the induced group was triggered by eGFP-GSDMD-N275. | ||
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− | <img src="https://static.igem.org/mediawiki/ | + | <div style="width: 90%; margin: 0 auto"> |
+ | <img src="https://static.igem.org/mediawiki/2018/b/b3/T--HZAU-China--basicPart4.png" width="100%" alt=""> | ||
+ | </div> | ||
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− | Figure 4. Hela GSDMD KO | + | <b>Figure 4.</b> Hela GSDMD KO cells were infected with <i>ΔsifA</i> SL1344 containing high copy number plasmids which express eGFP-GSDMD-N275 under the control of ATc. |
+ | Photos were captured 5 min, 30min, 1.5h after induction, respectively. | ||
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− | <img src="https://static.igem.org/mediawiki/ | + | <div style="width: 50%; margin: 0 auto"> |
+ | <img src="https://static.igem.org/mediawiki/2018/2/22/T--HZAU-China--basicPart5.png" width="100%" alt=""> | ||
+ | </div> | ||
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− | Figure 5. Ruptured cells in a field of view were counted. | + | <b>Figure 5.</b> Numbers of pyroptotic cells before and after ATc induction. Ruptured cells in a field of view were counted. |
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<h3>Reference</h3> | <h3>Reference</h3> | ||
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1. Ding, J. et al. Pore-forming activity and structural autoinhibition of the gasdermin family. Nature 535, 111-116, doi:10.1038/nature18590 (2016). | 1. Ding, J. et al. Pore-forming activity and structural autoinhibition of the gasdermin family. Nature 535, 111-116, doi:10.1038/nature18590 (2016). | ||
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Latest revision as of 23:04, 17 October 2018
N-terminal of GasderminD (1-275aa)
Pyroptosis is a form of lytic programmed cell death with inflammation. Recent studies reported that the N-terminal of GSDMD acts as an effector of pyroptosis. Full length GSDMD (GSDMD FL) is cleaved by Caspase 1, releasing the pore-forming domain (GSDMD-N275) which can oligomerize and make pores on the cell membrane. Formation of pores causes cell to swell, leading to membrane rupture and massive leakage of cytosolic contents1.
The N-terminal of GSDMD performs the function of pyroptosis in cells
We fused eGFP with GSDMD-N275 and GSDMD FL (full length), respectively. Then the corresponding plasmids were transfected into Hela GSDMD KO (knockout) cell. Cell microscopy showed that the cells transfected with GSDMD-N275 underwent pyroptosis while the cells with GSDMD FL did not (Figure 1). We also tested the cell viability though an ATP assay (CellTiter-Glo® Luminescent Cell Viability Assay) and demonstrated that GSDMD-N275 and mutants of GSDMD FL have different ability to induce pyroptosis (Figure 2).
Figure 1. Microscopy of the Hela GSDMD KO cells transfected with pCS2-eGFP-GSDMD FL and pCS2-eGFP-GSDMD-N275, respectively. Pyroptotic cells are pointed by red arrow.
Figure 2. Cell viability of the 293T cells transfected with pCS2-Flag-GSDMD FL, pCS2-Flag-GSDMD-N275, pCS2-Flag-GSDMD L290D, pCS2-Flag-GSDMD Y373D, pCS2-Flag-GSDMD A377D, respectively. Asterisks indicate the statistically significant differences. ATP-based cell viability was measured (n=6).
The N-terminal of GSDMD lyses bacteria
Expression of the N terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) in Salmonella enterica serovar Typhimurium str. SL1344 ΔsifA is under the control of Ptet. The colony-forming unit (CFU) was measured for counting the number of viable bacteria (Figure 3). The result shows that eGFP-GSDMD-N275 exhibits cytotoxicity to bacteria.
Figure 3. CFU comparison between the SL1344 ΔsifA cells with eGFP-GSDMD-N275 plasmid and with the empty vector. In each group, ATc (15μg/ml) was added into medium when bacteria grew to logarithmic phase (OD = 0.6~0.8). Vector refers to bacteria containing a high copy number plasmid which only expresses TetR under the control of Ptet . Bacterial colony-forming units (CFU) for vector and eGFP-GSDMD-N275 are shown in the logarithmic form (log10) (n = 3).
The N-terminal of GSDMD from lytic bacteria induces cell pyroptosis
Expression of the N-terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) is under the control of tet promoter in ΔsifA SL1344. Hela GSDMD KO cells were infected with ΔsifA SL1344. Inducer ATc (16μg/mL) was added 3h after infection. Microscopy shows that eGFP-GSDMD-N275 locates in cytoplasm after 5 min of induction and triggers pyroptosis after 30 min of induction (Figure 4). By counting the population of ruptured cells, there is a 1.96 fold-change between the induced group and the control group (Figure 5). So the pyroptosis of host cell in the induced group was triggered by eGFP-GSDMD-N275.
Figure 4. Hela GSDMD KO cells were infected with ΔsifA SL1344 containing high copy number plasmids which express eGFP-GSDMD-N275 under the control of ATc. Photos were captured 5 min, 30min, 1.5h after induction, respectively.
Figure 5. Numbers of pyroptotic cells before and after ATc induction. Ruptured cells in a field of view were counted.
Reference
1. Ding, J. et al. Pore-forming activity and structural autoinhibition of the gasdermin family. Nature 535, 111-116, doi:10.1038/nature18590 (2016).
Sequence and Features
Assembly Compatibility:
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]