Post Date
Dec 5 2023

Orchestrating the Symphony of Genes - Unveiling the Role of Mask Protein

Picture a grand orchestra, with each musician playing a crucial role in creating a harmonious symphony. In a similar vein, researchers at the Department of Biology at SBASSE, LUMS, have uncovered a key 'conductor' in the biological orchestra of gene regulation controlling cell fates – the Mask protein. Just like a conductor leads an orchestra, the Mask protein in fruit flies directs the activity of cell fate specific genes, ensuring they play their parts at the right times. 
Research led by Ammad Shaukat and Mahnoor Hussain Bakhtiari, as the first authors under the supervision of Dr Muhammad Tariq, has been published in the prestigious journal Developmental Biology. Their study reveals that the Mask protein in fruit flies shares functional traits with the Trithorax group (trxG) proteins. Unlike the Polycomb group (PcG) proteins, which silence gene expression, trxG proteins play a pivotal role in sustaining the active state of genes, ensuring their continuous and proper expression.

This figure demonstrates the impact of Mask depletion on gene expression in fruit flies and its genetic interactions with other key proteins involved in gene regulation.

The study essentially explores how Mask operates at the molecular level. In every cell, genes are constantly being turned on and off, a process critical for proper functioning. Mask plays a role similar to a switch, helping to keep certain genes in the 'on' position. This is especially important during an organism's development, where precise gene activity patterns are essential for normal growth and formation of different cell types.
The research team found that Mask binds to areas in chromosomes marked by H3K27ac, a chemical tag indicating active gene regions. When Mask levels were reduced, these active regions showed changes in H3K27ac, leading to alterations in gene expression that are crucial for the development and identity of cells. They have also discovered that Mask counteracts repression by the PcG to ensure activation of cell type specific genes which are linked to maintenance of cell fates. 

Displayed here is the genome-wide binding profile of Mask, emphasizing its strong association with active gene regions and transcription start sites.

By examining fruit flies, a common model organism in genetics, the researchers identified that Mask interacts with specific sites in chromosomes where other trxG proteins are also present. When the Mask is not present, or its levels are altered, the normal pattern of gene activity is disrupted, leading to developmental abnormalities. Since Mask belongs to a specific class of proteins known as cell signaling factors, the study by Tariq Lab opens a new avenue that may help link cell signaling and cell fate maintenance in future. 
This discovery is akin to finding a new way to understand and potentially direct the biological orchestra in humans. It opens possibilities for new treatments for diseases, such as developmental disorders and cancers, where the genetic symphony goes awry. The conservation of this mechanism in flies and mammals suggests that the role of Mask may be a universal theme in the biological orchestras across species.