Lac Operon Boolean Models: Dynamical Robustness and Alternative Improvements
Montalva-Medel
M
author
Ledger
T
author
Ruz
G
A
author
Goles
E
author
2021
In Veliz-Cuba and Stigler 2011, Boolean models were proposed for the lac operon in Escherichia coli capable of reproducing the operon being OFF, ON and bistable for three (low, medium and high) and two (low and high) parameters, representing the concentration ranges of lactose and glucose, respectively. Of these 6 possible combinations of parameters, 5 produce results that match with the biological experiments of Ozbudak et al., 2004. In the remaining one, the models predict the operon being OFF while biological experiments show a bistable behavior. In this paper, we first explore the robustness of two such models in the sense of how much its attractors change against any deterministic update schedule. We prove mathematically that, in cases where there is no bistability, all the dynamics in both models lack limit cycles while, when bistability appears, one model presents 30% of its dynamics with limit cycles while the other only 23%. Secondly, we propose two alternative improvements consisting of biologically supported modifications; one in which both models match with Ozbudak et al., 2004 in all 6 combinations of parameters and, the other one, where we increase the number of parameters to 9, matching in all these cases with the biological experiments of Ozbudak et al., 2004.
ELEMENTARY CELLULAR-AUTOMATA
CARBON CATABOLITE REPRESSION
GLUCOSE-LACTOSE DIAUXIE
ESCHERICHIA-COLI
BLOCK INVARIANCE
MAXIMUM SENSITIVITY
BETA-GALACTOSIDASE
BISTABLE BEHAVIOR
BISTABILITY
NETWORK
WOS:000645324300001
exported from refbase (show.php?record=1374), last updated on Thu, 10 Jun 2021 11:32:36 -0400
text
10.3390/math9060600
Montalva-Medel_etal2021
Mathematics
Mathematics
2021
continuing
periodical
academic journal
9
6
600
2227-7390