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Microbiol Biotechnol Rep | Volume 1, Issue 2
November 16-17, 2017 Atlanta, Georgia, USA
Annual Congress on
Mycology and Fungal Infections
The hnRNP-like yeast termination factor Nab3 can employ heterologous low complexity
domains in place of its essential low complexity domain
Travis Loya
Emory University, USA
Many RNA-binding proteins possess domains with biased amino acid content. A common property of these
low complexity domains (LCDs) is that they assemble into an ordered amyloid form, juxtaposing RNA
recognition motifs in a subcellular compartment in which RNA metabolism is focused. Yeast Nab3 is one such
protein that contains RNA-binding domains and a low complexity, glutamine/proline-rich, prion-like domain
that can self-assemble. Nab3 also contains a region of structural homology to human hnRNP-C that resembles a
leucine zipper which can oligomerize. We determined that the LCD and the human hnRNP-C homology domain
of Nab3 are experimentally separable, as cells are viable with either segment, but not when both are missing. In
exploiting the lethality of deleting these regions of Nab3, we tested if heterologous prion-like domains known
to assemble into amyloid can substitute for the native sequence. These results suggest there are different
cross-functional classes of amyloid-forming LCDs and that appending merely any assembly-competent
LCD to Nab3 does not restore function or rescue viability. As LCD’s are known to be mediators of RNA
granule formation in vivo , we are also exploring the subcellular localization of wild-type and mutant Nab3’s
in response to sugar deprivation. Wild-type Nab3 localizes to granules during sugar deprivation, while LCD
mutants show a loss of localization, showing this to be an LCD-mediated process. Analysis of Nab3 has provided
insights into the diversity of LCD mediated interactions as well as a means of dissecting their function in the cell.
Biography
Travis Loya is a third year graduate student in the Biochemistry, Cell, and Developmental Biology program in the Laney graduate school at Emory University. He
has participated in multiple short reviews for F1000 as well as published five manuscripts and one review article during his time in the lab of Dr. Danny Reines.
He plans to graduate in 2018 and move on to an academic post-doctoral position continuing to explore the emerging field of low complexity domain containing
proteins and their roles in biology.