Limits...
Effects of multimerization on the temporal variability of protein complex abundance.

Häkkinen A, Tran H, Yli-Harja O, Ingalls B, Ribeiro AS - BMC Syst Biol (2013)

Bottom Line: We show that, although multimerization increases noise by reducing the mean number of functional complexes it can reduce noise in comparison with a monomer, when abundance of the functional proteins are comparable.Alternatively, reduction in noise occurs if both monomeric and multimeric forms of the protein are functional.Moreover, we find that multimerization either increases the response time to external signals or decreases the correlation between number of functional complexes and protein production kinetics.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
We explore whether the process of multimerization can be used as a means to regulate noise in the abundance of functional protein complexes. Additionally, we analyze how this process affects the mean level of these functional units, response time of a gene, and temporal correlation between the numbers of expressed proteins and of the functional multimers. We show that, although multimerization increases noise by reducing the mean number of functional complexes it can reduce noise in comparison with a monomer, when abundance of the functional proteins are comparable. Alternatively, reduction in noise occurs if both monomeric and multimeric forms of the protein are functional. Moreover, we find that multimerization either increases the response time to external signals or decreases the correlation between number of functional complexes and protein production kinetics. Finally, we show that the results are in agreement with recent genome-wide assessments of cell-to-cell variability in protein numbers and of multimerization in essential and non-essential genes in Escherichia coli, and that the effects of multimerization are tangible at the level of genetic circuits.

Show MeSH

Related in: MedlinePlus

Change in mean levels due to homodimerizationRelative mean levels of homodimers P1,1 and the total number of molecules  as a function of the mean monomer level . The dashed line indicates a gain of one half. The inset shows linear gain.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3750523&req=5

Figure 1: Change in mean levels due to homodimerizationRelative mean levels of homodimers P1,1 and the total number of molecules as a function of the mean monomer level . The dashed line indicates a gain of one half. The inset shows linear gain.

Mentions: We simulated the models with several parameters values of dM, αM, kM, and kP as described above. Taking μ as the mean level of the molecules of interest and as the mean level in the monomeric model, the ratio is plotted as a function of in Figure 1. (The mean is determined by dM, kM, and kP).


Effects of multimerization on the temporal variability of protein complex abundance.

Häkkinen A, Tran H, Yli-Harja O, Ingalls B, Ribeiro AS - BMC Syst Biol (2013)

Change in mean levels due to homodimerizationRelative mean levels of homodimers P1,1 and the total number of molecules  as a function of the mean monomer level . The dashed line indicates a gain of one half. The inset shows linear gain.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750523&req=5

Figure 1: Change in mean levels due to homodimerizationRelative mean levels of homodimers P1,1 and the total number of molecules as a function of the mean monomer level . The dashed line indicates a gain of one half. The inset shows linear gain.
Mentions: We simulated the models with several parameters values of dM, αM, kM, and kP as described above. Taking μ as the mean level of the molecules of interest and as the mean level in the monomeric model, the ratio is plotted as a function of in Figure 1. (The mean is determined by dM, kM, and kP).

Bottom Line: We show that, although multimerization increases noise by reducing the mean number of functional complexes it can reduce noise in comparison with a monomer, when abundance of the functional proteins are comparable.Alternatively, reduction in noise occurs if both monomeric and multimeric forms of the protein are functional.Moreover, we find that multimerization either increases the response time to external signals or decreases the correlation between number of functional complexes and protein production kinetics.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
We explore whether the process of multimerization can be used as a means to regulate noise in the abundance of functional protein complexes. Additionally, we analyze how this process affects the mean level of these functional units, response time of a gene, and temporal correlation between the numbers of expressed proteins and of the functional multimers. We show that, although multimerization increases noise by reducing the mean number of functional complexes it can reduce noise in comparison with a monomer, when abundance of the functional proteins are comparable. Alternatively, reduction in noise occurs if both monomeric and multimeric forms of the protein are functional. Moreover, we find that multimerization either increases the response time to external signals or decreases the correlation between number of functional complexes and protein production kinetics. Finally, we show that the results are in agreement with recent genome-wide assessments of cell-to-cell variability in protein numbers and of multimerization in essential and non-essential genes in Escherichia coli, and that the effects of multimerization are tangible at the level of genetic circuits.

Show MeSH
Related in: MedlinePlus