title: High-affinity DNA-binding domains of replication protein A (RPA) direct SMARCAL1-dependent replication fork remodeling.
abstract: SMARCAL1 catalyzes replication fork remodeling to maintain genome stability. It is recruited to replication forks via an interaction with replication protein A (RPA), the major ssDNA-binding protein in eukaryotic cells. In addition to directing its localization, RPA also activates SMARCAL1 on some fork substrates but inhibits it on others, thereby conferring substrate specificity to SMARCAL1 fork-remodeling reactions. We investigated the mechanism by which RPA regulates SMARCAL1. Our results indicate that although an interaction between SMARCAL1 and RPA is essential for SMARCAL1 activation, the location of the interacting surface on RPA is not. Counterintuitively, high-affinity DNA binding of RPA DNA-binding domain (DBD) A and DBD-B near the fork junction makes it easier for SMARCAL1 to remodel the fork, which requires removing RPA. We also found that RPA DBD-C and DBD-D are not required for SMARCAL1 regulation. Thus, the orientation of the high-affinity RPA DBDs at forks dictates SMARCAL1 substrate specificity.
authors.affiliation: From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
authors.forename: Kamakoti P
authors.initials: KP
authors.lastname: Bhat
authors.affiliation: From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
authors.forename: Rémy
authors.initials: R
authors.lastname: Bétous
authors.affiliation: From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 david.cortez@vanderbilt.edu.
authors.forename: David
authors.initials: D
authors.lastname: Cortez
mesh_terms: D020816:Amino Acid Motifs; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D051716:Replication Protein A / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured
chemical_list: D004277:DNA, Single-Stranded; D051716:Replication Protein A; C412482:SMARCAL1 protein, human; D004265:DNA Helicases
keywords: ATPase; DNA Damage Response; DNA Repair; DNA Replication; Fork Regression; Genomic Instability; Replication Protein A; SMARCAL1