Presenter: Sarah Quist
Authors: Sarah Quist, Lauren Brooks
Faculty Advisor: Lauren Brooks
Institution: Utah Valley University
Alzheimer’s disease is a neurodegenerative disorder characterized by a decline in cognitive function. The hallmark event in the brain of an Alzheimer’s patient is the aggregation of misfolded proteins referred to as amyloid beta (Aβ) plaque. Many of the microbiome bacteria also produce an amyloid type of protein called curli. The function of curli fibers is involved in adhesion to surfaces, cell aggregation and biofilm formation. Through molecular mimicry, bacterial curli proteins may act as prion proteins and elicit cross-seeding of the misfolding of Aβ proteins. There are variations in the genetic organization of the curli gene among the different bacterial genera. It is a question as to whether the variability is related to the taxonomy of bacteria. Using NCBI (National Center for Biotechnology Information), we compiled a comprehensive database of the curli protein, starting with a seed sequence from E. coli curli protein subunit CsgA (P28307). We used local BLAST to identify sequences. Each sequence was blasted until no new sequences were returned. This data was filtered to include only full protein sequences. We used RStudio and MEGA for the data analysis and the creation of charts and graphs. We discovered that there is a higher than anticipated variety in the amino acid sequences of curli proteins. We also discovered that the amino acid sequence of the curli protein cannot be predicted based on the taxonomy.