creator Tsai, Yu-tseng advisor Xiang, Jialing The tumor suppressor gene, Bax, plays a critical role in tumor progression through regulating cell apoptosis. Mutations on the BAX gene often result in silencing its expression and the loss of pro-death ability. However, there is a unique Bax isoform, BaxΔ2, recently discovered in these Bax mutated cancer cells. BaxΔ2 isoform shows higher pro-apoptotic activity than Baxα. Unlike the parental Baxα, BaxΔ2 does not target mitochondria and forms aggregates in cytosol. There is a unique 10-amino-acid peptide in the N-terminus of BaxΔ2 protein possible function as a special signal. Two serines in this region are predicted as potential phosphorylation sites for regulation of the protein activity. To test this hypothesis, we mutated both serines (SS) into non-phosphorylatable alanines (AA) by site-directed mutagenesis approach. Both BaxΔ2 wild type (BaxΔ2-SS) and mutants (BaxΔ2-AA) were tagged with GFP, which allows us to monitor the protein expression and cellular localization in live cells. Here, we found that the distribution patterns of BaxΔ2-AA and BaxΔ2-SS were similar and appeared as aggregates in cytosol. BaxΔ2-AA mutant also possessed the similar pro-apoptotic activity with BaxΔ2-SS wild type. These results suggested that the two serines in BaxΔ2 unique oligopeptide might not play a critical role in BaxΔ2 localization and pro-death activity under the current ectopic expression conditions. Further study is needed to have better understanding of phosphorylation in contribution to unique behavior of BaxΔ2. Submitted by Liana Khananashvili (khananashvili@iit.edu) on 2014-12-18T19:37:53Z No. of bitstreams: 2 YT-Thesis.pdf: 487374 bytes, checksum: 2a8fc9c537bed28bb42367951c9c990d (MD5) Signed title page.pdf: 22954 bytes, checksum: 8f4dd7e5a6920c99593e99647693b081 (MD5) Made available in DSpace on 2014-12-18T19:37:53Z (GMT). No. of bitstreams: 2 YT-Thesis.pdf: 487374 bytes, checksum: 2a8fc9c537bed28bb42367951c9c990d (MD5) Signed title page.pdf: 22954 bytes, checksum: 8f4dd7e5a6920c99593e99647693b081 (MD5) Previous issue date: 2014-07 M.S. in Biology, July 2014 2014 2014-07 http://hdl.handle.net/10560/3373 en Thesis born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access BIOL / Biology Illinois Institute of Technology Affiliated department