Difference between revisions of "Part:BBa K2332312"

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E-cadherin (Preproprotein, Mus Musculus)

This gene encodes E-cadherin, a calcium-dependent cell adhesion molecule that functions in the establishment and maintenance of epithelial cell morphology during embryongenesis and adulthood. The encoded preproprotein undergoes proteolytic processing to generate a mature protein.

Usage and Biology

Cadherin proteins are a family of cell adhesion proteins with over 120 members.

Figure 1: Adherens Junction - Cadherin Mediated Cell-Cell Adhesion.

UCSF iGEM 2011 has created a BioBrick of only the extracellular domain of E-Cadherin (Mouse) BBa_K644000 but no BioBrick encoding the full E-cadherin protein has been submitted until now. BBa_K644000 also lacked detailed characterisation and the source was imprecise. Furthermore, we know now that E-cadherin requires interaction of its cytosolic domain for the production of stable cell-cell connections. (see Alberts 6th Ed. 2015, Ch. 19, p. 1040).

This gene was given to the UCL iGEM team 2017 by Prof. Stephen Price (UCL, not part of iGEM) after we searched for cadherin proteins suitable for our project. However, no sequence was known of the plasmid we were given and we sequenced the plasmid ourselves. Consecutive BLAST analysis showed a 99% similarity with Mus musculus cadherin 1 (Cdh1), mRNA: NCBI Reference Sequence: NM_009864.3, NCBI.

Figure 2: BLAST Results from E-cadherin. /n Cadherin_pro- Cadherin proteins are activated through cleavage of a prosequence in the late Golgi. This prevents cadherin aggregation in the early stage of the secretory pathway. This domain corresponds to the folded region of the prosequence, and is termed the prodomain. The prodomain shows structural resemblance to the cadherin domain, but lacks all the features known to be important for cadherin-cadherin interactions.

Three silent mutations were added into the sequence via side directed mutagenesis in order to remove one EcoRI and two PstI sites. Afterwards we sequence confirmed the entire gene.

Experimental approach

Vector Considerations

For testing this coding part we used pcDNA3, a standard mammalian expression plasmid, as a vector. We, thereby, created BBa_K2332313, our E-cadherin gene flanked by a CMV promoter and a bGH poly(A) tail. The pre-existing 5'- and 3'-UTR and the strong promoter ensure efficient expression of E-cadherin after transfection.

Chassis Considerations

Choosing the correct chassis for your experiments is of equal importance to choosing the correct gene.

Since we wanted to test cell-cell aggregation induced by the E-cadherin gene, we therefore chose a mammalian cell line that naturally does not express E-cadherin and is commonly used in cadherin research, Chinese Hamster Ovary (CHO) cells. Even though they naturally lack E-cadherin expression they still maintain alpha- and beta-catenin expression, the two proteins that are essential for E-cadherin's connection to the actin cortex of the cell.

Sequence and Features

Functional Parameters