Roles of Skp2 and SAC in Preserving Genomic Integrity
Standing
Undergraduate
Type of Proposal
Oral Presentation
Faculty
Faculty of Science
Proposal
Skp2 is an F-box protein of the SCF complex whose overexpression has been documented in a variety of human cancers. It is an oncogene known for its role in targeting the tumor suppressor p27 for proteasomal degradation at the end of G1 to promote entry of the cell into S phase. However, in-vivo studies in mice and Drosophila have shown a novel role of Skp2 as a potential tumor suppressor. The loss of Skp2 results in reduced ability to enter mitosis and subsequent polyploidy. However, when Skp2 mutant cells do enter mitosis, cells are delayed in prometaphase/metaphase due to activation of the Spindle Assembly Checkpoint (SAC), and mitosis is aberrant. Previous studies in the Swan lab have shown that knocking out Mad2, a critical component of the SAC, in Skp2 mutant cells is able to rescue the mitotic delay but it also results in failed chromosome segregation, chromosome breakage, increased polyploidy, and increased apoptosis, indicating that the SAC may be important for preventing further genome instability of Skp2 mutant cells. This project aims to first, confirm those results, and second, assess whether those results are indeed due to a SAC-specific role of Mad2, as opposed to a novel function of Mad2, by testing two other SAC components – BubR1 and Bub3. RNAi will be expressed in the wings to knock down Skp2 and the SAC components, and wing discs of larvae will be examined for the degree of polyploidy, potential mitotic defects, the mitotic index and the level of apoptosis.
Location
University of Windsor
Grand Challenges
Viable, Healthy and Safe Communities
Roles of Skp2 and SAC in Preserving Genomic Integrity
University of Windsor
Skp2 is an F-box protein of the SCF complex whose overexpression has been documented in a variety of human cancers. It is an oncogene known for its role in targeting the tumor suppressor p27 for proteasomal degradation at the end of G1 to promote entry of the cell into S phase. However, in-vivo studies in mice and Drosophila have shown a novel role of Skp2 as a potential tumor suppressor. The loss of Skp2 results in reduced ability to enter mitosis and subsequent polyploidy. However, when Skp2 mutant cells do enter mitosis, cells are delayed in prometaphase/metaphase due to activation of the Spindle Assembly Checkpoint (SAC), and mitosis is aberrant. Previous studies in the Swan lab have shown that knocking out Mad2, a critical component of the SAC, in Skp2 mutant cells is able to rescue the mitotic delay but it also results in failed chromosome segregation, chromosome breakage, increased polyploidy, and increased apoptosis, indicating that the SAC may be important for preventing further genome instability of Skp2 mutant cells. This project aims to first, confirm those results, and second, assess whether those results are indeed due to a SAC-specific role of Mad2, as opposed to a novel function of Mad2, by testing two other SAC components – BubR1 and Bub3. RNAi will be expressed in the wings to knock down Skp2 and the SAC components, and wing discs of larvae will be examined for the degree of polyploidy, potential mitotic defects, the mitotic index and the level of apoptosis.