Undergraduate Honors Theses

Thesis Defended

Spring 2011

Document Type


First Advisor



U2 auxiliary factor (U2AF) is an important component of the eukaryotic spliceosome and is essential for pre-mRNA splicing in Schizosaccharomyces pombe. Studies have shown that RNA binding is required for U2AF’s role in spliceosome assembly. We have found temperature sensitive mutants of U2AF that inhibit splicing of most pre-mRNA transcripts at a restrictive temperature. However, some transcripts are still spliced at the restrictive temperature, suggesting a splicing pathway independent of U2AF. Determining if the temperature sensitive mutants of U2AF are binding the mRNA is an important first step towards identifying an alternative splice pathway. If the U2AF mutants fail to bind the mRNA, this could suggest the existence of a non-canonical splicing pathway that functions in the absence of U2AF. Splicing could occur through the presence of a strong 5’ splicing sequence, or perhaps through the actions from an as yet unidentified splice factor. The following work lays the groundwork for determining the mRNA binding capability of the temperature sensitive U2AF mutants.