Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro
Plasmin (PLS) and urokinase-type plasminogen activator (UPA) are ubiquitous proteases that regulate the extracellular environment. Although they are secreted in inactive forms, they can activate each other through proteolytic cleavage. This mutual interplay creates the potential for complex dynamics...
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| Format: | Article |
| Language: | en_US |
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Elsevier
2014
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| Online Access: | http://hdl.handle.net/1721.1/92049 https://orcid.org/0000-0003-1080-4005 https://orcid.org/0000-0001-7387-3572 |
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| author | Venkatraman, Lakshmi Li, Huipeng Dewey, C. Forbes White, Jacob K. Bhowmick, Sourav S. Yu, Hanry Tucker-Kellogg, Lisa White, Jacob K. |
| author2 | Massachusetts Institute of Technology. Department of Biological Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Biological Engineering Venkatraman, Lakshmi Li, Huipeng Dewey, C. Forbes White, Jacob K. Bhowmick, Sourav S. Yu, Hanry Tucker-Kellogg, Lisa White, Jacob K. |
| author_sort | Venkatraman, Lakshmi |
| collection | MIT |
| description | Plasmin (PLS) and urokinase-type plasminogen activator (UPA) are ubiquitous proteases that regulate the extracellular environment. Although they are secreted in inactive forms, they can activate each other through proteolytic cleavage. This mutual interplay creates the potential for complex dynamics, which we investigated using mathematical modeling and in vitro experiments. We constructed ordinary differential equations to model the conversion of precursor plasminogen into active PLS, and precursor urokinase (scUPA) into active urokinase (tcUPA). Although neither PLS nor UPA exhibits allosteric cooperativity, modeling showed that cooperativity occurred at the system level because of substrate competition. Computational simulations and bifurcation analysis predicted that the system would be bistable over a range of parameters for cooperativity and positive feedback. Cell-free experiments with recombinant proteins tested key predictions of the model. PLS activation in response to scUPA stimulus was found to be cooperative in vitro. Finally, bistability was demonstrated in vitro by the presence of two significantly different steady-state levels of PLS activation for the same levels of stimulus. We conclude that ultrasensitive, bistable activation of UPA-PLS is possible in the presence of substrate competition. An ultrasensitive threshold for activation of PLS and UPA would have ramifications for normal and disease processes, including angiogenesis, metastasis, wound healing, and fibrosis. |
| first_indexed | 2024-09-23T13:00:28Z |
| format | Article |
| id | mit-1721.1/92049 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:00:28Z |
| publishDate | 2014 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/920492022-10-01T12:25:05Z Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro Venkatraman, Lakshmi Li, Huipeng Dewey, C. Forbes White, Jacob K. Bhowmick, Sourav S. Yu, Hanry Tucker-Kellogg, Lisa White, Jacob K. Massachusetts Institute of Technology. Department of Biological Engineering Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Department of Mechanical Engineering Dewey, C. Forbes White, Jacob K. Plasmin (PLS) and urokinase-type plasminogen activator (UPA) are ubiquitous proteases that regulate the extracellular environment. Although they are secreted in inactive forms, they can activate each other through proteolytic cleavage. This mutual interplay creates the potential for complex dynamics, which we investigated using mathematical modeling and in vitro experiments. We constructed ordinary differential equations to model the conversion of precursor plasminogen into active PLS, and precursor urokinase (scUPA) into active urokinase (tcUPA). Although neither PLS nor UPA exhibits allosteric cooperativity, modeling showed that cooperativity occurred at the system level because of substrate competition. Computational simulations and bifurcation analysis predicted that the system would be bistable over a range of parameters for cooperativity and positive feedback. Cell-free experiments with recombinant proteins tested key predictions of the model. PLS activation in response to scUPA stimulus was found to be cooperative in vitro. Finally, bistability was demonstrated in vitro by the presence of two significantly different steady-state levels of PLS activation for the same levels of stimulus. We conclude that ultrasensitive, bistable activation of UPA-PLS is possible in the presence of substrate competition. An ultrasensitive threshold for activation of PLS and UPA would have ramifications for normal and disease processes, including angiogenesis, metastasis, wound healing, and fibrosis. Singapore-MIT Alliance Computational and Systems Biology Flagship Project Singapore-MIT Alliance Computational and Systems Biology Programme Grants 2014-12-08T17:27:04Z 2014-12-08T17:27:04Z 2011-10 2011-04 Article http://purl.org/eprint/type/JournalArticle 00063495 1542-0086 http://hdl.handle.net/1721.1/92049 Venkatraman, Lakshmi, Huipeng Li, C. Forbes Dewey, Jacob K. White, Sourav S. Bhowmick, Hanry Yu, and Lisa Tucker-Kellogg. “Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro.” Biophysical Journal 101, no. 8 (October 2011): 1825–1834. © 2011 Biophysical Society https://orcid.org/0000-0003-1080-4005 https://orcid.org/0000-0001-7387-3572 en_US http://dx.doi.org/10.1016/j.bpj.2011.08.054 Biophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Elsevier Elsevier |
| spellingShingle | Venkatraman, Lakshmi Li, Huipeng Dewey, C. Forbes White, Jacob K. Bhowmick, Sourav S. Yu, Hanry Tucker-Kellogg, Lisa White, Jacob K. Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title | Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title_full | Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title_fullStr | Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title_full_unstemmed | Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title_short | Steady States and Dynamics of Urokinase-Mediated Plasmin Activation In Silico and In Vitro |
| title_sort | steady states and dynamics of urokinase mediated plasmin activation in silico and in vitro |
| url | http://hdl.handle.net/1721.1/92049 https://orcid.org/0000-0003-1080-4005 https://orcid.org/0000-0001-7387-3572 |
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