Barrett, The Honors College Thesis/Creative Project Collection
Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.
Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.
In eukaryotes, most messenger RNA precursors (pre-mRNA) undergo extensive processing, leading to the cleavage of the transcript followed by the addition of a poly(A) tail. This process is executed by a large complex known as the Cleavage and Polyadenylation Complex (CPC). Its central subcomplex, the Cleavage and Polyadenylation Specificity Factor…
In eukaryotes, most messenger RNA precursors (pre-mRNA) undergo extensive processing, leading to the cleavage of the transcript followed by the addition of a poly(A) tail. This process is executed by a large complex known as the Cleavage and Polyadenylation Complex (CPC). Its central subcomplex, the Cleavage and Polyadenylation Specificity Factor (CPSF) complex is responsible for recognizing a short hexameric element AAUAAA located at the 3’end in the nascent mRNA molecule and catalyzing the pre-mRNA cleavage. In the round nematode C. elegans, the cleavage reaction is executed by a subunit of this complex named CPSF3, a highly conserved RNA endonuclease. While the crystal structure of its human ortholog CPSF73 has been recently identified, we still do not understand the molecular mechanisms and sequence specificity used by this protein to induce cleavage, which in turn would help to understand how this process is executed in detail. Additionally, we do not understand in additional factors are needed for this process. In order to address these issues, we performed a comparative analysis of the CPSF3 protein in higher eukaryotes to identify conserved functional domains. The overall percent identities for members of the CPSF complex range from 33.68% to 56.49%, suggesting that the human and C. elegans orthologs retain a high level of conservation. CPSF73 is the protein with the overall highest percent identity of the CPSF complex, with its active site-containing domain possessing 74.60% identity with CPSF3. Additionally, we gathered and expressed using a bacterial expression system CPSF3 and a mutant, which is unable to perform the cleavage reaction, and developed an in vitro cleavage assay to test whether CPSF3 activity is necessary and sufficient to induce nascent mRNA cleavage. This project establishes tools to better understand how CPSF3 functions within the CPC and sheds light on the biology surrounding the transcription process as a whole.
