Jason Chobirko
Jason Chobirko
Year: 2019
Faculty Advisor: Gaurav Moghe
Mentor: Lars Kruse

Investigating the molecular mechanisms of BAHD acyltransferase substrate specificity

In order to both survive and thrive plants need to be able to respond to environmental stresses. One of the ways in which they do this is through secondary metabolites (also known as specialized metabolites). For example, some secondary metabolites are toxic and protect against herbivory while others attract pollinators or protect the plant against harmful UV light. In the Moghe lab, we are interested in an enzyme family that was found to be involved in several important secondary pathways called BAHD acyltransferases. In general, BAHD enzymes transfer an acyl chain from a CoA-activated donor molecule to an acceptor molecule. BAHD acyltransferases are a relatively large enzyme family with often more than 100 genes in higher plants and different BAHD enzymes have been shown to use a variety of substrates. My project revolved around the diversity of BAHD substrates such as anthocyanins, aromatic and aliphatic alcohols and amines, alkaloids and others. First, I aimed to identify if there was conserved gene structure across the Viridiplatae in order to better understand the evolutionary history of the BAHD acyltransferase family. Then, I attempted to determine if there are conserved amino acid sequence between BAHDs of different species that use the same substrate class.
By analyzing BAHD genes across representatives of mayor plant lineages for which genomes are available, I discovered that BAHD genes differ significantly in the length and numbers of introns which can be used to investigate the evolutionary history of BAHD enzymes in more detail. By structurally analyzing BAHD enzymes along within a phylogenetic context, I found that there were many regions of conservation across the BAHD enzymes with similar function. By mutating residues within these regions and then performing enzyme assays we are currently trying to find out the role of these residues for substrate specificity. Once complete, this work can be applied to other enzyme families involved in secondary to further understand how substrate specificity evolves.

My Experience

Working as a BTI intern in the Moghe lab at Cornell University has been an amazing learning experience! Although the project that I worked on was mostly computational, I was still able to learn a lot about wet lab work like cloning and transformations. My mentor, Lars Kruse, was a wealth of knowledge about plants and BAHD acyltransferases and he was incredibly helpful since my previous research work was with vertebrates. Gaurav Moghe helped me to further develop my prior foundations in genetics and data analysis through R and Python scripting to complete much of the scientific computational work. Because of this, I became hooked on how versatile and powerful Python can be and I will continue to develop my coding and data analysis skillset to help advance my scientific career. I intend to take full advantage of all the knowledge and experiences that I had this summer to go on to complete my Undergraduate degree and apply for both Graduate school and the NSF Graduate Research Fellowship Program so that I may devote my scientific curiosity and skillset to furthering research.