Team:UT Dallas/project part3

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Revision as of 23:27, 27 September 2013

Quorum sensing molecules are naturally used by S. Mutans to regulate population growth and competency. At normal levels, Competency Stimulating Peptide (CSP) allows a local population of S. Mutans to share plasmids and grow. When the concentration of CSP gets too high CSP activates a genetic pathway that causes some cells to activate cell-death. This allows the colony to remain at sustainable levels. We can take advantage of this natural population control to cause the equilibrium concentration of S. mutans in the oral cavity to decrease drastically. E. coli can produce CSP constitutively at a high rate. When placed in the mouth, these engineered E. coli will raise the concentration of CSP and cause the death of any nearby S. mutans cells. The natural quorum signaling system involves five gene products encoded by: ComA, ComB, ComC, ComD, ComE. The comC gene encodes a competence-stimulating peptide (CSP) precursor. ComC and ComDE lie adjacent on the chromosome and, together with their gene products, constitute a peptide (CSP)-signaling system including a generating pathway (comC) and a responding pathway (comDE). The other two genes, cslA and cslB, are located in a separate region of the chromosome and encode a CSP-specific secretion apparatus consisting of an ATP-binding cassette (ABC) transporter (ComA) and its accessory protein (ComB), which are involved in the processing and export of the CSP.

What We Did: We attempted to use these quorum sensing molecules which are naturally used by S. Mutans. When placed in the mouth, our engineered E. Coli cells sense the presence of S.mutans and raise the concentration of CSP and cause the death of any nearby harmful cells.

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-<span class="title_spans">The Com System</span><br><br>
+Quorum sensing molecules are naturally used by S. Mutans to regulate population growth and competency. At normal levels, Competency Stimulating Peptide (CSP) allows a local population of S. Mutans to share plasmids and grow. When the concentration of CSP gets too high CSP activates a genetic pathway that causes some cells to activate cell-death. This allows the colony to remain at sustainable levels. We can take advantage of this natural population control to cause the equilibrium concentration of <i>S. mutans</i> in the oral cavity to decrease drastically. <i>E. coli</i> can produce CSP constitutively at a high rate. When placed in the mouth, these engineered <i>E. coli</i> will raise the concentration of CSP and cause the death of any nearby <i>S. mutans</i> cells. The natural quorum signaling system involves five gene products encoded by: ComA, ComB, ComC, ComD, ComE. The comC gene encodes a competence-stimulating peptide (CSP) precursor. ComC and ComDE lie adjacent on the chromosome and, together with their gene products, constitute a peptide (CSP)-signaling system including a generating pathway (comC) and a responding pathway (comDE). The other two genes, cslA and cslB, are located in a separate region of the chromosome and encode a CSP-specific secretion apparatus consisting of an ATP-binding cassette (ABC) transporter (ComA) and its accessory protein (ComB), which are involved in the processing and export of the CSP.<br><br>
-<b>How it Works</b><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A solution to this problem involves the use of quorum sensing molecules which are naturally used by S. Mutans to regulate population growth, competency, and many other uses that are undiscovered. At normal levels, Competency Stimulating Peptide (CSP) allows a local population of S. Mutans to share plasmids and grow stronger. However, when the concentration of CSP gets too high CSP activates a genetic pathway that causes some cells to activate cell-death. This allows the colony to remain at sustainable levels. We plan to take advantage of this natural population control to cause the equilibrium concentration of S. mutans in the oral cavity to decrease drastically. We will create a plasmid which, when expressed in E. coli, will be able to produce CSP constitutively at a high rate. When placed in the mouth, these E. coli will then raise the concentration of CSP and cause the death of any nearby S. mutans cells. <br><br>
-<b>The quorum signaling system involves five gene products encoded by:</b>
-<blockquote><li>ComA
-<li>ComB
-<li>ComC
-<li>ComD
-<li>ComE</blockquote>
-<br>
-<b>comCDE</b> <br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The comC gene encodes a competence-stimulating peptide (CSP) precursor. ComC and ComDE lie adjacent on the chromosome and, together with their gene products, constitute a peptide (CSP)- signaling system including a generating pathway (comC) and a responding pathway (comDE). The other two genes, cslA and cslB, are located in a separate region of the chromosome and encode a CSP-specific secretion apparatus consisting of an ATP-binding cassette (ABC) transporter (ComA) and its accessory protein (ComB), which are involved in the processing and export of the CSP.<br><br>
-<b>What We Did</b><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;We attempted to use these  quorum sensing molecules which are naturally used by S. Mutans to regulate population growth, competency, and many other uses that are undiscovered. When placed in the mouth, our E. Coli cells would then raise the concentration of CSP and cause the death of any nearby S. mutans cells.<br><br>
-<img src="http://i826.photobucket.com/albums/zz188/lana_khazma/fancy%20stuff/comstuff_zps2e546eb2.png" border="0" alt=" photo comstuff_zps2e546eb2.png"/ width=400>
+<b>What We Did:</b> We attempted to use these quorum sensing molecules which are naturally used by <i>S. Mutans</i>. When placed in the mouth, our engineered <i>E. Coli</i> cells sense the presence of <i>S.mutans</i> and raise the concentration of CSP and cause the death of any nearby harmful cells.