Date of Award

Spring 5-6-2024

Degree Type

Dissertation/Thesis

Degree Name

Master of Science in Integrative Biology

Department

Molecular and Cellular Biology

Committee Chair/First Advisor

Anton Bryantsev

Second Advisor

Brandon Carpenter

Third Advisor

Thomas Leeper, Carol Chrestensen

Abstract

Understanding mechanisms of intracellular sorting is a fundamental inquiry of cell biology. We used the B-body and protein Bruno (Bru) as a model to study the formation of nuclear domains that are membraneless organelles inside the cell nucleus. Specifically, we sought to identify protein sequences that regulate Bru's affinity to B-bodies and protein aggregation. We generated various Bru mutants and subsequently tested them in vivo using fluorescence microscopy. We found that the protein solubility of Bru is determined through an interplay of RNA recognition motifs (RRMs) and intrinsically disordered regions (IDRs). Using truncation analysis, we identified a 31-amino acid region within IDR1 that may regulate Bru solubility via phosphorylation of three key amino acids. Complementarily, in a reverse genetic screen, we identified Doa kinase as a factor modulating Bru's affinity toward B-bodies. In summary, Bru accumulation at B-bodies requires all RRMs that determine the specificity, while phosphorylation of IDR1 may be needed for the protein’s release from B-bodies. Our study provides a detailed mechanistic insight into the formation of nuclear domains by RNA-binding proteins.

Comments

NSF grant 2042814

Available for download on Saturday, May 09, 2026

Share

COinS