IU biochem professor finds 2 cancer-fighting traits in yeast protein

An IU biochemist has discovered two protein traits that could keep cancer at bay.
Assistant professor Matthew Bochman used a yeast protein called Hrq1 in his study to model the human protein cell RecQ4.

Yeast cells lacking Hrq1 were especially susceptible to cancer, Bochman found.
Cells low in Hrq1 were hypersensitive to toxic lesions on DNA strands called DNA interstrand crosslinks and to an enzyme substance called telomerase, which protects the ends of chromosomes and keeps them from fraying.

The new work found that Hrq1 affected several aspects of telomerase biology, according to a press release.

This includes inhibiting over-growth of the substance at the tips of chromosomes, and at locations where lethal breaks in both strands of the DNA double helix had occurred.
While not enough telomerase can promote aging, too much can give way to uncontrollable cancer growth.

In addition to inhibiting telomerase, Bochman and fellow researches discovered Hrq1 promotes genetic integrity by advancing inter-strand crosslink repair.

This suggests Hrq1 cells’ strong sensitivity to inter-strand crosslinks may be a first line of defense against the dangerous lesions, the release said.

Continued research may show why mutations of human RecQ4 lead to unstable genetic info and, in turn, disease.

Three syndromes are already known to be effects of RecQ4 mutations — Bloom syndrome, Werner syndrome and Rothmund-Thomson syndrome.

Each are associated with an increased predisposition to cancer.

“We want to continue exploiting yeast as a simple model to spread our net wide to learn more about Hrq1’s genetic and physical interactions in the cell, how Hrq1 inhibits telomerase, when and how it functions during crosslink repair,” Bochman said in the release.

— Ashley Jenkins