Beta-catenin as a molecular switch in the regulation of transition of cell-cell adhesion to fusion in Drosophila Melanogaster

Understanding cell fusion is an important aspect of life. Cancer has plagued the world for years. It is by understanding more about cancer on a cellular level that solutions can be forged. This poster highlights one of the signalling proteins of the Wnt pathway, -Catenein (Trans- membrane glycoprotein), and its involvement in cell adhesion to fusion.

In cell and developmental biology, cell adhesion and anchoring is a pivotal and fundamental aspect that is looked at. This poster introduces the basic understanding of how -Catenein contributes to cell binding via help from the mutant, E-catenin. These two signalling protein structures complement each other to form the E-cathenin Cadhedrin complex which is the main structure responsible for adhesion amongst cells. It gives a Brief history on Beta catenin and its structure, as well as a brief introduction about the mutation of -catenin as armadillo in Drosphila melangaster.

Cell anchoring junctions was described as automatic, mechanical attaching cells (and their cytoskeletons) to their neighbours (cell-cell) or to the extracellular matrix (cell-matrix). Beta-catenin (or -catenin), belongs to the family of catenins that are proteins that play main roles in adherens junctions and mainly cell adhesion and is a part of the cadherin protein complexes and it can do two functions; regulate the controlled coordination of the cell-to-cell adhesion and gene transcription. It is the main component that is responsible of the creation and maintenance of the epithelial cell layer.

The poster highlights the functioning of Beta catenin and E cadherin, where after its translation from MRNA, the classic adherent protein is transported to the cell membrane. The cadherin establishes itself as a Trans-membrane protein and with distinct cytoplasmic and extracellular domains. The extracellular domain which is responsible for the cadherins ability to link adjacent cells present incoherent a compatible type which includes five characteristic domains. These cadherin domains interact with domains on neighboring cells in a calcium dependent manner. In the present of calcium ions, individual cadherins pair up to form dimers on one side of the intracellular junctions. These dimers then bind to other dimers on the opposite. When calcium is removed from the environment the cadherin molecules fail to bind and cell to cell adhesion is disrupted.

This poster is supported by an experiment done by Youki Takezawa, Keiichi Yoshida, Kenji Miyado, Masahiro Sato and their team on Beta catenin as a molecular switch that regulates transition of cell to cell adhesion to fusion within sperm and oocyte. This experiment showed that by Biochemical analysis, the complexes, Beta catenin and E catenin forms a new complex that aids in cell adhesion.

Since cancer is an out of control growing, replicating number of cells, The poster also highlights some of the diseases proposed by non functional Beta catenin and states that the build up of Beta catenin on the N terminus of the armadillo mutation, results in continuos gene transcription which results in a variety of cancers.

It is known that an oocyte merges with only one sperm when it is fertilized that creates a single cell with two nuclei that then goes through some complex processes. The curiosity of knowing how the fusion of egg and sperm really happens since during fusion a new cell two nuclei is formed and how does cell anchoring and adhesion contribute to cancer. More knowledge of cell adhesion is crucial since little is known about what really happens in binding of the two nucleuses inside the egg. It would contribute more knowledge to embryogenesis as well contribute to the pioneering research area of sex selection as well as aiding in the much too long fight against cancer.

In concluding, the poster identified how Beta catenin acts as a molecular switch that regulates transition of cell to cell adhesion to fusion by the usage of dimmers and mutant E catenin as well as stated the mutation of beta catenin to form the Armadillo protein that was found in Drosophila Melangaster.

**Diagrams shown are referenced from various journals and other individuals work and are listed lastly in the References section. References were cited using Chicago style manual edition 16.

References

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Dimitrovagen677s09.weebly.com,. 2014. 'Dimitrovagen677s09 - Home'. http://dimitrovagen677s09.weebly.com/.

Jyi.org,. 2014. http://www.jyi.org/issue/beta-catenin-mediated-wnt-signaling-as-a-marker-for-characterization-of-human-bone-marrow-derived-connective-tissue-progenitor-cells/.

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Php.med.unsw.edu.au,. 2014. '2011 Group 5 Project - Cellbiology'. http://php.med.unsw.edu.au/cellbiology/index.php?title=2011_Group_5_Project&mobileaction=toggle_view_mobile.

R, Willert. 2014. 'Beta-Catenin: A Key Mediator Of Wnt Signaling. - Pubmed - NCBI'. Ncbi.Nlm.Nih.Gov. http://www.ncbi.nlm.nih.gov/pubmed/9529612.

Takezawa, Youki, Keiichi Yoshida, Kenji Miyado, Masahiro Sato, Akihiro Nakamura, Natsuko Kawano, and Keiichi Sakakibara et al. 2011. '-Catenin Is A Molecular Switch That Regulates Transition Of Cell-Cell Adhesion To Fusion'. Scientific Reports 1. doi:10.1038/srep00068.

Tian, Xinrui, Zhuola Liu, Bo Niu, Jianlin Zhang, Thian Kui Tan, So Ra Lee, Ye Zhao, David C. H. Harris, and Guoping Zheng. 2011. 'E-Cadherin/-Catenin Complex And The Epithelial Barrier'. Journal Of Biomedicine And Biotechnology 2011: 1-6. doi:10.1155/2011/567305.

Web.stanford.edu,. 2014. '-Catenin/Armadillo | The Wnt Homepage'. http://web.stanford.edu/group/nusselab/cgi-bin/wnt/b-catenin.

Wijnhoven BP, et al. 2014. 'E-Cadherin-Catenin Cell-Cell Adhesion Complex And Human Cancer. - Pubmed - NCBI'. Ncbi.Nlm.Nih.Gov. http://www.ncbi.nlm.nih.gov/pubmed/10931041.

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