10. Determination of Genes Required to Unclog Clogged Cellular Channels

Samantha Turk Ball State University, Danielle Overton Ball State University, Cade Orchard Ball State University, Chris Indovina Ball State University, Sarah Engle Ball State University, Sheldon Watts Ball State University
Faculty Sponsor(s): Eric Rubenstein Ball State University
Protein degradation is necessary to recycle proteins that are only needed for a short time, discard damaged proteins, or remove proteins that behave aberrantly. One way in which proteins behave aberrantly is by persistently engaging a cellular channel called the translocon. The translocon is a protein channel that allows proteins to cross the endoplasmic reticulum membrane. Hrd1 is a ubiquitin ligase that targets proteins that clog the translocon for degradation by ligating multiple copies of a protein called ubiquitin to clogging proteins. This process is conserved in yeast and man. Ubiquitin ligases rarely function without the assistance of additional proteins. Further, loss of Hrd1 does not completely prevent the destruction of translocon-clogging proteins. Therefore, we hypothesized that other proteins function with Hrd1 or in parallel mechanisms to unclog the translocon. A previous master’s student performed a yeast growth-based genome-wide screen to identify genes required for protein degradation at the translocon. This screen identified ~150 genes that behave similarly to HRD1. Because large-scale screens may yield false positives, we performed small-scale growth assays to validate roles for identified genes in protein degradation. Our small-scale growth assays support potential roles for 28 genes in regulating abundance of translocon-clogging proteins. We are currently performing cycloheximide chase and western blot analyses to determine abundance and degradation kinetics of translocon-clogging proteins in yeast lacking the validated genes. Since a protein found in low-density lipoproteins (“bad cholesterol”) clogs the translocon under certain circumstances, validated genes may represent therapeutic targets for elevated cholesterol.
Poster Presentation

When & Where

Irwin Library 3rd Floor