Nucleoli movement and Cell Shape, How are they related?
Researchers identify the nucleoli movement having an effect on the shape of cells.
A team of researchers has found that the health of cells is maintained by two types of movement of their nucleoli. What contributes to healthy cell functions and what effects will the human health face if this is disrupted can be understood by this dual motion within a surrounding fluid.
The senior author of the study and an assistant professor in New York University’s Department of Physics, Alexandra Zidovska explains nucleolar malfunction could lead to diseases including cancer. Therefore, to create new diagnostics and therapies for certain human afflictions, it is important to understand the process responsible for the maintenance of nucleolar shape and motion.
Discoveries made recently show that some of the cellular components, that was seen previously as necessary for holding a cell together did not have membranes. Since then, scientists have been trying to understand the forces that maintain the integrity of the cells without these membranes and have finally found a link between the nucleoli movement and cell shape.
The nature of this behavior has been observed. Similar to oil and water, these compartments
act as liquid droplets made of a material that does not mix with the fluid surrounding them. This process is called liquid-liquid separation. This process is now one of the key cellular organizing principles.The best-known example of such a cellular liquid was considered in this study. The nucleolus, which is vital to protein synthesis in the cell, residing inside the cell nucleus, was focused upon in this study.
Zidovska, who co-authored the study with Shannon Haley, an undergraduate in NYU’s College of Arts and Science at the time of the work and now a doctoral student at the University of California at Berkeley and Christina Caragine, an NYU doctoral student, explains, “This liquid-like nature of the nucleolus has been studied earlier but its relationship with the surrounding liquid remains unknown. Considering the surrounding liquid, the nucleoplasm containing the entire human genome, this relationship is particularly fascinating.
Yet, how the two fluids interact with each other is unclear. In order to understand this dynamic better, the researches observed the fusion and motion of human nucleoli in live human cells along with monitoring their size, shape, and smoothness of their surface. The team had created the method for studying the fusion of the nucleolar droplets in 2018 and this was reported in the Physical Review Letters journal.
Their most recent study shows two types of nucleolar pair movements or “dances”, which is an unexpected correlated motion before its fusion and individual motion. They also found that the nucleolar interface smoothness is susceptible to both changes in the packing state of the genome surrounding the nucleoli and the gene expression.
Zidovska says, “The biggest droplet inside the cell nucleus, Nucleolus, serves a crucial role in stress response, human aging and in general protein synthesis while it exists in this special state. As the nucleoli are surrounded by fluid containing our genome, the nucleoli movement stirs the genes around them. The genome in the surrounding fluid and nucleoli exist in a sensitive balance. Therefore, any change in either the genome or the nucleoli can influence the other. If this state is disrupted, it can potentially lead to disease.”
This study appeared in the eLife journal.
The National Science Foundation and the National Institutes of Health supported by grants to this research.
Author: Prathibha HC
