Date of Completion

5-1-2015

Project Advisor(s)

Daniel Schwartz; Victoria Robinson; Paulo Verardi

University Scholar Major

Biological Sciences

Disciplines

Cell Biology | Cellular and Molecular Physiology | Molecular Biology

Abstract

Protein phosphorylation is a post-translational modification (PTM) that is ubiquitous in regulating cellular processes. It is the most common PTM used in signal translation. Protein kinases are the class of enzymes that catalyze the transfer of a phosphate group from ATP to a specific amino acid on a substrate protein. In eukaryotes, kinases generally add a phosphate to serine, threonine, or tyrosine residues. Short linear patterns in the amino acid sequence of the substrate protein help guide the protein kinase to the correct residue to be phosphorylated. However, these patterns, or “motifs,” as well as the complete list of substrates for each kinase are largely unknown. A method known as ProPeL (Proteomic Peptide Library) can be utilized to discover motifs, and thus potential target substrates, of a protein kinase-of-interest. For this project, ProPeL and the visualization tool known as pLogo (Probability Logo Generator) have been utilized to examine the specificity motifs of two DYRK family protein kinases, DYRK2 and DYRK4. Our preliminary data suggests that the substrate specificities for DYRK2 and DYRK4 are similar to the canonical member, DYRK1a; however, distinct differences have been found. For example, DYRK2 may have a higher stoichiometry of protein phosphorylation at tyrosine sites, and DYRK4 may not exhibit the typical preference for serine over threonine when phosphorylating substrates. For both DYRK2 and DYRK4, additional data will need to be collected to obtain more statistically significant results.

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