Identifying the Nuclear Localization Signal of the Arabidopsis Thaliana MADS Box Transcription Factor Flowering Locus C

Abstract

The goal of this undergraduate honours research project is to design a research strategy to identify the Nuclear Localization Signal (NLS) of the Arabidopsis thaliana MADs box transcription factor Flowering Locus C (FLC), and to begin the cloning and plant transformation of key controls required for this objective. Nuclear localization of proteins requires a specific amino acid sequence, called the Nuclear Localization Signal (NLS). The NLS of FLC has not yet been characterized, though previous work on Arabidopsis has established conserved structural-functional domains within FLC. The NLS within other MADs box proteins varies in its specific sequence, but is generally located within the MADs box domain around the N-terminal region of the polypeptide, which is a conserved region amongst MADs box proteins. I have created an FLC gene construct to be used with the GreenGate cloning system which will ultimately serve as a positive control showing nuclear localization in planta. I have also established the components necessary for the creation of a negative control line of Arabidopsis expressing GFP alone, which is not expected to nuclearly localize. Finally, I have completed a literature review to explore the existing understanding of NLS structure in general, in MADs box transcription factor proteins, and in other plant transcription factors, to propose mutations that might disrupt the NLS sequence within FLC. This work aims to fill a knowledge gap in regards to the mechanism of nuclear localization of FLC and will ultimately contribute to our understanding of nuclear localization in general.

Department: Biology 

Faculty Mentor: Dr. Melissa Hills