Co-evolution of functional motifs and H2A.X in plant DDR

المفاهيم الأساسية

Identification of BCP1-4 as functional counterparts of MDC1 in plant DDR.

الملخص

The study identified BCP1-4 proteins with tBRCT domains involved in DNA damage response (DDR) in plants. BCP4 binds γH2A.X and acts as a functional counterpart of MDC1, while BCP1 shows similarity to human PAXIP1. The phylogenetic analysis supports the independent evolution of plant and metazoan counterparts. Mutants lacking BCP proteins showed sensitivity to DNA damage, confirming their role in DDR. BCP4 interacts with NBS1, suggesting a role in recruiting the MRN complex.

الإحصائيات

Induction of DNA damage triggers rapid phosphorylation of histone H2A.X (γH2A.X).
BCP4 binds γH2A.X and acts as a functional counterpart of MDC1.
Mutants lacking BCP proteins showed sensitivity to DNA damage.
BCP4 interacts with NBS1, potentially recruiting the MRN complex.

اقتباسات

"BCP4 binds phosphorylated H2A.X and co-localizes with DNA damage-induced foci."
"BCP3 and BCP4 are likely functional counterparts of MDC1."
"Mutants lacking BCP proteins show reduced homologous recombination rates."

الرؤى الأساسية المستخلصة من

Identification of plants functional counterparts of the metazoan Mediator of DNA Damage Checkpoint 1

by Lorkovic,Z. ... في www.biorxiv.org 05-19-2023

https://www.biorxiv.org/content/10.1101/2023.05.19.541430v2

استفسارات أعمق

How do the conserved regions TQxD, SQSQ, and DTQ in BCP3 and BCP4 contribute to DDR?

The conserved regions TQxD, SQSQ, and DTQ in BCP3 and BCP4 play crucial roles in DNA damage response (DDR) mechanisms. These regions serve as potential docking sites for other DDR effectors that may be shared with animals. The TQxD motif is particularly interesting as it resembles the TQxF motifs found in human MDC1, which are essential for interactions with RNF8. This suggests that the TQxD motif could potentially mediate interactions with key DDR proteins involved in signaling and repair processes.
Additionally, the SQSQ motif may have a role in protein-protein interactions or post-translational modifications related to DDR. While the exact functions of these conserved regions need further investigation, their presence indicates their importance in coordinating responses to DNA damage within plant cells.

How might the absence of certain DDR components in red algae shed light on alternative mechanisms for dealing with DNA damage?

The absence of certain DNA damage response (DDR) components in red algae raises intriguing questions about how these organisms cope with DNA damage without traditional repair pathways observed in other organisms. Red algae are known to thrive under extreme environmental conditions where exposure to genotoxic agents can be high.
One possible explanation is that red algae have evolved alternative mechanisms for dealing with DNA damage. These mechanisms could involve unique repair pathways or specialized proteins that function differently from conventional DDR components found in plants or animals. Understanding these alternative strategies employed by red algae could provide valuable insights into novel ways of maintaining genome integrity under challenging environmental conditions.

What implications does the independent evolution of plant and metazoan counterparts have for understanding DDR mechanisms?

The independent evolution of plant and metazoan counterparts of mediator of DNA damage response (MDC1) has significant implications for our understanding of DNA damage response (DDR) mechanisms across different evolutionary lineages. By identifying functional counterparts like AtMDC1 (BCP4), we gain insights into how essential processes such as γH2A.X recognition and recruitment of downstream effectors have evolved independently but still converge on similar outcomes.
This independent evolution highlights the versatility and adaptability of DDR systems across diverse organisms facing distinct challenges related to genome maintenance. Studying these parallel evolutionary paths can provide a more comprehensive view of fundamental biological processes like DDR while also revealing unique adaptations specific to each lineage's needs.