Interactome analysis reveals a n 1 ovel role for RAD6 in the regulation of proteasome activity and localization in response to DNA damage

It has been long understood that DNA represents the building blocks of life. Working like a code, it gives the instructions for how each and every mechanism required for life should be structured and executed. As such, it needs to be near perfect. Any mistake or imperfection can have dramatic implications, especially if it replicates before it has the chance to be repaired. Fortunately, DNA recognizes this and has mechanisms in place to try and repair itself. The two known to the scientific community at this time are described as "error-prone" and "error-free" DNA repair. "Error prone" DNA damage repair pathway uses the translesion DNA synthesis (TLS) mechanism to insert correct or incorrect nucleotides to repair the damaged DNA, while "error free" DNA damage repair pathway functions with the undamaged sister duplex, which helps create a precise repair and the correct inheritance of genetic information. Many different substances work in tandem to help these processes occur. Ubiquitination, for example, is a critical posttranslational protein modification that is catalyzed by a series of 56 enzymes including the E1 ubiquitin activation enzyme, E2 ubiquitin-conjugating enzyme, and E3 57 ubiquitin-protein ligase. RAD6 is an E2 ubiquitin-conjugating enzyme that cooperates with a whole host of other enzymes, acting as a node to direct different DNA damage repair pathways, determining whether or not DNA is repaired in an "error prone" or "error free" manner.

To fully understand the role of RAD6 in determining DNA damage repair pathways An et al. performed a proteomic analysis and identified the protein-protein interaction (PPI) dynamics of RAD6. To do this, they needed to rely on a wide array of tools used to study these very mechanisms, such as the Amplite Fluorimetric Proteasome 20S Activity Assay Kit, which uses LLVY-R110 as a fluorogenic indicator of proteasome activity, producing a bright fluorescent glow that allows for the easy tracing of proteasome activity.

The results of this study suggest that RAD6 enhances proteasome activity and nuclear translocation by promoting the degradation of the proteasome inhibitor PSMF1 and the nuclear lamin B receptor LBR. This indicates a novel pathway for determining DNA damage repair, which helps shed more light on how the process works, allowing for more effective genetic treatments moving forward. Monitoring the activity of proteasome 20S was key to this study and was made possible with the Amplite Fluorimetric Proteasome 20S Activity Assay Kit. The robust and reliable results delivered by this tool allow for researchers to report confidently on their findings, which empowers research moving forward. Understanding the inner-workings and functions of DNA is essential for any advance in modern medicine, and this study, using the quality equipment provided by Amplite, has helped pushed this line of research further, opening the door for even more groundbreaking studies in the future.

References

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1. An, Hongli, et al. "Interactome analysis reveals a novel role for RAD6 in the regulation of proteasome activity and localization in response to DNA damage." Molecular and cellular biology 37.6 (2017): e00419-16.