Part:BBa_K1072023
Fus1 Promotor
BBa_K1072023 is a induced promotor, originating from S.cerevisiae.In the endogenous MAP-kinase pathway in S.cerevisiae, third messenger,ste12, will stimulate fus1 promoter, which results in mating of the yeast.However the sequence of fus1 contains Pst1 restrict enzyme site, we use the method of overlap extension to achieve the purpose of site-directed mutagenesis ("CTGCAG" to "CTGGAG").
This part is an improvement of BBa_K775004 of 2012 TU delft team.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Team INSA-UPS France 2017 usage of BBa_K1072023 in Pichia pastoris strain : activation of pFUS1 promoter upon diacetyl detection by Odr-10 receptor
We wanted to build a gene with a diacetyl inducible expression using Odr-10/pFUS1 system.
To do so, we designed the construction (see Figure 1) to characterize pFUS1 activation. Indeed, when diacetyl binds to Odr-10 (BBa_K1072010) a cascade of activation of Ste proteins (endogenous to P. pastoris) leads to the binding of Ste12 on pFUS1 promoter, and so to an increase of transcription from pFUS1 promoter (revealed by the RFP reporter gene (BBa_J04450).
As a control, we firstly demonstrated the activity of the pGAP promotor (see BBa_K431009) present in the yeast vector pPICZα we used).
We tested the functionality of the complete system Odr-10/pFUS1 by growing the cells on a media specifically designed to induce the activation of Ste proteins (http://2017.igem.org/Team:INSA-UPS_France/Protocols).
Absorbance and florescent production by P. pastoris strain having integrated the empty plasmid or the plasmid containing Odr-10/pFUS-RFP system was followed over the time on a microplate reader. Results are presented in Figure 2.
No difference was observed between the negative control and the strain expressing Odr-10/pFUS1-RFPwith 500 µM diacetyl. However, when diacetyl was present at higher concentration (i.e. 1000 µM), significant differences were observed between both strain. This data demonstrate the functionality of the complete detection pathway, including the pFUS1 functionality.
Team Estonia_TUIT characterization of BBa_K1072023 (pFUS1)
pFUS1 controls the expression of the FUS1 gene that encodes a membrane protein from the yeast mating pathway. Fus1 protein localizes to the tip of the shmoo (a protrusion formed during yeast mating) (Lim et al., 2014). Fus1 protein coordinates the signaling, cell fusion, and polarization events required for the fusion of yeast cells. Transcription of FUS1 is mediated in haploid yeast by four pheromone response elements (PRE) of the pFUS1 promoter (Hagen et al., 1991). To induce the pFUS1, we used the α-factor to activate the mating pathway in MATa yeast strain.
pFUS1 promoter activity was induced with 1 μg/mL of α-factor. We observed gradual pheromone-dependent activation of the pFUS1 promoter (Fig. 1) throughout the experiment. When α-factor was not present (uninduced strain), the level of GFP fluorescence was similar to those observed in the control DOM090 strain (data not shown). Fus1 protein is associated with the tip of the shmoo involved in a mating process. Since the α-factor is not removed from the environment and mating did not happen, it leads to the constant activation of pFUS1 promoter and, as a result, an increase in GFP fluorescence throughout the experiment (Figure 1).
References:
- Lim, W., Mayer, B., & Pawson, T. (2014). Cell Signaling : Principles and mechanisms. Cell Signaling. https://doi.org/10.1201/9780429258893
- Lawrence, C. W. (2004). Cellular functions of DNA polymerase ζ and REV1 protein. Advances in Protein Chemistry, 69, 167–203. https://doi.org/10.1016/S0065-3233(04)69006-1
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