How molecular partners form dynamic scaffolding for protein machinery

phys.org | 12/6/2018 | Staff
Mijac (Posted by) Level 3
Click For Photo: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/2018/5c092ab042eee.jpg

Scientists at St. Jude Children's Research Hospital have mapped key details of how molecular partners regulate assembly of protein-making factories called ribosomes.

The findings, published in the journal Nature Communications, add a piece to the puzzle of ribosome assembly. The results may also suggest a pathway to new cancer drugs that target the hyperactive protein-production machinery that helps drive proliferation. The research provides a foundation for understanding the molecular mechanism of toxicity in amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease.

Richard - Kriwacki - PhD - Member - St

Richard Kriwacki, Ph.D., a member of the St. Jude Department of Structural Biology, led the research.

Ribosomes are assembled within the nucleolus in the cell's nucleus. The nucleolus lacks a membrane, making it different from most other cell structures. The nucleolus is organized via a process called liquid-liquid phase separation, which is like the colorful, undulating blobs in lava lamps that dynamically form, shift and fuse.

Studies - Kriwacki - Colleagues - Protein - Nucleophosmin

In previous studies, Kriwacki and colleagues found that a protein called nucleophosmin helped organize the nucleolus and to regulate ribosome construction. However, a central mystery was how nucleophosmin interacted with an essential molecular partner called SURF6 to adapt the structure of the nucleolus as it assembled ribosomes.

"We knew SURF6 was an essential gene, and that if you delete it, the cell dies; but its functional role wasn't understood," said one of the paper's authors, Diana Mitrea, Ph.D., a staff scientist in Kriwacki's laboratory. "We knew SURF6 interacts with nucleophosmin. But in this paper, we went deeper, showing how SURF6 modulates the scaffold structure that holds the components of the nucleolus."

Researchers - Droplets - Nucleolus - Properties - State—as

Researchers created nucleophosmin-containing droplets that mimicked the nucleolus' physical properties. They found that in the more liquid state—as when nucleophosmin is fostering the assembly of ribosomes—the protein partners with itself. However, when the ribosomes have assembled their subunits, SURF6 binds to vacant sites on the nucleophosmin molecule, which...
(Excerpt) Read more at: phys.org
Wake Up To Breaking News!
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!