Selective interactions at pre-replication complexes categorize baseline and dormant origins

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• DNA replication in metazoans initiates from specific baseline origins.
• Dormant origins are typically inactive but can be activated during replication stress.
• The mechanism distinguishing baseline from dormant origins remains unclear.

Purpose of the Study:

• To elucidate the mechanism controlling replication origin selection in metazoans.
• To investigate the role of RecQL4 in regulating DNA replication initiation.
• To understand how cells recover from replication stress.

Main Methods:

• Investigated protein-DNA interactions at replication origins.
• Utilized biochemical assays to study protein complex formation.
• Analyzed the role of phosphorylated RecQL4 (pRecQL4) in origin regulation.

Main Results:

• Dormant origins selectively bind pRecQL4 during normal cell proliferation.
• pRecQL4 inhibits the binding of the MTBP-TICRR/TRESLIN complex to dormant origins.
• pRecQL4 facilitates MTBP-TICRR/TRESLIN dissociation during replication stress, enabling origin activation and recovery.

Conclusions:

• pRecQL4 is a key regulator of replication origin choice in metazoans.
• The interaction between pRecQL4 and MTBP-TICRR/TRESLIN is crucial for both origin selection and replication stress response.
• This mechanism ensures efficient and accurate genome duplication.