My Father accidentally left me in the combine in the middle of a corn field during his first babysitting experience. He claims that when he came back to get me two hours later, I looked very content. Twenty-plus years later, I am again content looking at plants and playing in the soil.
I am a PhD student in Caren’s lab, and my current research involves two projects. The first is characterization of a novel protein, which was isolated from a yeast-two-hybrid screen for interactors with the ethylene receptor, ETR1. ETR1-Interacting Protein 1 (EIP1) was of interest, because it also interacted (in the yeast-two-hybrid) with a portion of CTR1, the next known downstream component from the ethylene receptors. Initial analysis of an eip1 loss-of-function mutants reveal that EIP1 may have a role in cell elongation, at both the seedling and the adult stage. eip1 mutant seedlings are smaller than wild type, and the adult plants have smaller more compact rosettes than wild type. A closer look at the epidermal surface of rosette leaf cells, reveal that the cells in the mutant are smaller than wild type. Over-expression of EIP1 compliments the mutant’s phenotype in the adult stage (the seedling phenotype has not been tested yet). Furthermore after observing the affects of over-expressing EIP1 in different ethylene-impaired mutant backgrounds, I have found that EIP1 may require ETR1 for proper function. Using the amiRNA resource made available by Weigel et al, I hope to have an additional eip1 mutant to characterize soon.
My second project involves investigating the nature of the relationship between the ethylene receptor ETR1 and the Raf-like kinase CTR1, both of which are negative regulators of ethylene-signaling. Previously in our lab, ETR1 was shown to physically interact with the amino-terminal, non-catalytic region of CTR1, and the same CTR1 amino-terminal region can interact with its own kinase domain in vitro (Shockey and Chang, unpublished). Thus we propose a model in which upon ethylene binding to the ETR1 receptor, ETR1 and CTR1 lose their direct interaction, and this allows the CTR1 amino-terminal region to autoinhibit the CTR1 kinase activity through direct interaction. We are currently testing this model using BiFC techniques.
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