Browse
Submit Data
Databases
API
Help

Dataset Information

70 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rad54, the motor of homologous recombination.

ABSTRACT: Homologous recombination (HR) performs crucial functions including DNA repair, segregation of homologous chromosomes, propagation of genetic diversity, and maintenance of telomeres. HR is responsible for the repair of DNA double-strand breaks and DNA interstrand cross-links. The process of HR is initiated at the site of DNA breaks and gaps and involves a search for homologous sequences promoted by Rad51 and auxiliary proteins followed by the subsequent invasion of broken DNA ends into the homologous duplex DNA that then serves as a template for repair. The invasion produces a cross-stranded structure, known as the Holliday junction. Here, we describe the properties of Rad54, an important and versatile HR protein that is evolutionarily conserved in eukaryotes. Rad54 is a motor protein that translocates along dsDNA and performs several important functions in HR. The current review focuses on the recently identified Rad54 activities which contribute to the late phase of HR, especially the branch migration of Holliday junctions.

SUBMITTER: Mazin AV

PROVIDER: S-EPMC2827677 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Rad54, the motor of homologous recombination.

Mazin Alexander V AV Mazina Olga M OM Bugreev Dmitry V DV Rossi Matthew J MJ

DNA repair 20100120 3

Homologous recombination (HR) performs crucial functions including DNA repair, segregation of homologous chromosomes, propagation of genetic diversity, and maintenance of telomeres. HR is responsible for the repair of DNA double-strand breaks and DNA interstrand cross-links. The process of HR is initiated at the site of DNA breaks and gaps and involves a search for homologous sequences promoted by Rad51 and auxiliary proteins followed by the subsequent invasion of broken DNA ends into the homolo ...[more]

PMID: 20089461

Similar Datasets

Functions of the Snf2/Swi2 family Rad54 motor protein in homologous recombination.

Project description:Homologous recombination is a central pathway to maintain genomic stability and is involved in the repair of DNA damage and replication fork support, as well as accurate chromosome segregation during meiosis. Rad54 is a dsDNA-dependent ATPase of the Snf2/Swi2 family of SF2 helicases, although Rad54 lacks classical helicase activity and cannot carry out the strand displacement reactions typical for DNA helicases. Rad54 is a potent and processive motor protein that translocates on dsDNA, potentially executing several functions in recombinational DNA repair. Rad54 acts in concert with Rad51, the central protein of recombination that performs the key reactions of homology search and DNA strand invasion. Here, we will review the role of the Rad54 protein in homologous recombination with an emphasis on mechanistic studies with the yeast and human enzymes. We will discuss how these results relate to in vivo functions of Rad54 during homologous recombination in somatic cells and during meiosis. This article is part of a Special Issue entitled: Snf2/Swi2 ATPase structure and function.

| S-EPMC3171615 | biostudies-literature

Rad54 Phosphorylation Promotes Homologous Recombination by Balancing Rad54 Mobility and DNA Binding.

Project description:The repair of DNA double-strand breaks by homologous recombination is of crucial importance for maintaining genomic stability. Two major players during this repair pathway are Rad51 and Rad54. Previously, it was shown that Rad54 exists as a monomer or oligomer when bound to DNA and drives the displacement of Rad51 by translocating along the DNA. Moreover, phosphorylation of Rad54 was reported to stimulate this clearance of Rad51 from DNA. However, it is currently unclear how phosphorylation of Rad54 modulates its molecular-structural function and how it affects the activity of monomeric or oligomeric Rad54 during the removal of Rad51. To examine the impact of Rad54 phosphorylation on a molecular-structural level, we applied molecular dynamics simulations of Rad54 monomers and hexamers in the absence or presence of DNA. Our results suggest that 1) phosphorylation of Rad54 stabilizes the monomeric form by reducing the interlobe movement of Rad54 monomers and might therefore facilitate multimer formation around DNA and 2) phosphorylation of Rad54 in a higher-order hexamer reduces its binding strength to DNA, which is a requirement for efficient mobility on DNA. To further address the relationship between the mobility of Rad54 and its phosphorylation state, we performed fluorescence recovery after photobleaching experiments in living cells, which expressed different versions of the Rad54 protein. Here, we could measure that the phosphomimetic version of Rad54 was highly mobile on DNA, whereas a nonphosphorylatable mutant displayed a mobility defect. Taken together, these data show that the phosphorylation of Rad54 is a critical event in balancing the DNA binding strength and mobility of Rad54 and might therefore provide optimal conditions for DNA translocation and subsequent removal of Rad51 during homologous recombination repair.

| S-EPMC6486526 | biostudies-literature

Rad54: the Swiss Army knife of homologous recombination?

Project description:Homologous recombination (HR) is a ubiquitous cellular pathway that mediates transfer of genetic information between homologous or near homologous (homeologous) DNA sequences. During meiosis it ensures proper chromosome segregation in the first division. Moreover, HR is critical for the tolerance and repair of DNA damage, as well as in the recovery of stalled and broken replication forks. Together these functions preserve genomic stability and assure high fidelity transmission of the genetic material in the mitotic and meiotic cell divisions. This review will focus on the Rad54 protein, a member of the Snf2-family of SF2 helicases, which translocates on dsDNA but does not display strand displacement activity typical for a helicase. A wealth of genetic, cytological, biochemical and structural data suggests that Rad54 is a core factor of HR, possibly acting at multiple stages during HR in concert with the central homologous pairing protein Rad51.

| S-EPMC1616967 | biostudies-literature

NUCKS1 promotes RAD54 activity in homologous recombination DNA repair.

Project description:NUCKS1 (nuclear ubiquitous casein kinase and cyclin-dependent kinase substrate 1) is a chromatin-associated, vertebrate-specific, and multifunctional protein with a role in DNA damage signaling and repair. Previously, we have shown that NUCKS1 helps maintain homologous recombination (HR) DNA repair in human cells and functions as a tumor suppressor in mice. However, the mechanisms by which NUCKS1 positively impacts these processes had remained unclear. Here, we show that NUCKS1 physically and functionally interacts with the DNA motor protein RAD54. Upon exposure of human cells to DNA-damaging agents, NUCKS1 controls the resolution of RAD54 foci. In unperturbed cells, NUCKS1 prevents RAD54's inappropriate engagement with RAD51AP1. In vitro, NUCKS1 stimulates the ATPase activity of RAD54 and the RAD51-RAD54-mediated strand invasion step during displacement loop formation. Taken together, our data demonstrate that the NUCKS1 protein is an important new regulator of the spatiotemporal events in HR.

| S-EPMC7659731 | biostudies-literature

TLK1-mediated RAD54 phosphorylation spatio-temporally regulates Homologous Recombination Repair.

Project description:Environmental agents like ionizing radiation (IR) and chemotherapeutic drugs can cause severe damage to the DNA, often in the form of double-strand breaks (DSBs). Remaining unrepaired, DSBs can lead to chromosomal rearrangements, and cell death. One major error-free pathway to repair DSBs is homologous recombination repair (HRR). Tousled-like kinase 1 (TLK1), a Ser/Thr kinase that regulates the DNA damage checkpoint, has been found to interact with RAD54, a central DNA translocase in HRR. To determine how TLK1 regulates RAD54, we inhibited or depleted TLK1 and tested how this impacts HRR in human cells using a ISce-I-GR-DsRed fused reporter endonuclease. Our results show that TLK1 phosphorylates RAD54 at three threonines (T41, T59 and T700), two of which are located within its N-terminal domain (NTD) and one is located within its C-terminal domain (CTD). Phosphorylation at both T41 and T59 supports HRR and protects cells from DNA DSB damage. In contrast, phosphorylation of T700 leads to impaired HRR and engenders no protection to cells from cytotoxicity and rather results in repair delay. Further, our work enlightens the effect of RAD54-T700 (RAD54-CTD) phosphorylation by TLK1 in mammalian system and reveals a new site of interaction with RAD51.

| S-EPMC10484734 | biostudies-literature

Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination.

Project description:Homologous recombination (HR) helps maintain genome integrity, and HR defects give rise to disease, especially cancer. During HR, damaged DNA must be aligned with an undamaged template through a process referred to as the homology search. Despite decades of study, key aspects of this search remain undefined. Here, we use single-molecule imaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes, switches the search from the diffusion-based pathways characteristic of the basal HR machinery to an active process in which DNA sequences are aligned via an ATP-dependent molecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donor template strands, enabling the search to take place within a migrating DNA bubble-like structure that is bound by replication protein A (RPA). Our results reveal that Rad54, working together with RPA, fundamentally alters how DNA sequences are aligned during HR.

| S-EPMC7418177 | biostudies-literature

Nek1 Regulates Rad54 to Orchestrate Homologous Recombination and Replication Fork Stability.

Project description:Never-in-mitosis A-related kinase 1 (Nek1) has established roles in apoptosis and cell cycle regulation. We show that human Nek1 regulates homologous recombination (HR) by phosphorylating Rad54 at Ser572 in late G2 phase. Nek1 deficiency as well as expression of unphosphorylatable Rad54 (Rad54-S572A) cause unresolved Rad51 foci and confer a defect in HR. Phospho-mimic Rad54 (Rad54-S572E), in contrast, promotes HR and rescues the HR defect associated with Nek1 loss. Although expression of phospho-mimic Rad54 is beneficial for HR, it causes Rad51 removal from chromatin and degradation of stalled replication forks in S phase. Thus, G2-specific phosphorylation of Rad54 by Nek1 promotes Rad51 chromatin removal during HR in G2 phase, and its absence in S phase is required for replication fork stability. In summary, Nek1 regulates Rad51 removal to orchestrate HR and replication fork stability.

| S-EPMC5503685 | biostudies-literature

The translocation activity of Rad54 reduces crossover outcomes during homologous recombination.

Project description:Homologous recombination (HR) is a template-based DNA double-strand break repair pathway that requires the selection of an appropriate DNA sequence to facilitate repair. Selection occurs during a homology search that must be executed rapidly and with high fidelity. Failure to efficiently perform the homology search can result in complex intermediates that generate genomic rearrangements, a hallmark of human cancers. Rad54 is an ATP dependent DNA motor protein that functions during the homology search by regulating the recombinase Rad51. How this regulation reduces genomic exchanges is currently unknown. To better understand how Rad54 can reduce these outcomes, we evaluated several amino acid mutations in Rad54 that were identified in the COSMIC database. COSMIC is a collection of amino acid mutations identified in human cancers. These substitutions led to reduced Rad54 function and the discovery of a conserved motif in Rad54. Through genetic, biochemical and single-molecule approaches, we show that disruption of this motif leads to failure in stabilizing early strand invasion intermediates, causing increased crossovers between homologous chromosomes. Our study also suggests that the translocation rate of Rad54 is a determinant in balancing genetic exchange. The latch domain's conservation implies an interaction likely fundamental to eukaryotic biology.

| S-EPMC11229335 | biostudies-literature

Nap1 stimulates homologous recombination by RAD51 and RAD54 in higher-ordered chromatin containing histone H1.

Project description:Homologous recombination plays essential roles in mitotic DNA double strand break (DSB) repair and meiotic genetic recombination. In eukaryotes, RAD51 promotes the central homologous-pairing step during homologous recombination, but is not sufficient to overcome the reaction barrier imposed by nucleosomes. RAD54, a member of the ATP-dependent nucleosome remodeling factor family, is required to promote the RAD51-mediated homologous pairing in nucleosomal DNA. In higher eukaryotes, most nucleosomes form higher-ordered chromatin containing the linker histone H1. However, the mechanism by which RAD51/RAD54-mediated homologous pairing occurs in higher-ordered chromatin has not been elucidated. In this study, we found that a histone chaperone, Nap1, accumulates on DSB sites in human cells, and DSB repair is substantially decreased in Nap1-knockdown cells. We determined that Nap1 binds to RAD54, enhances the RAD54-mediated nucleosome remodeling by evicting histone H1, and eventually stimulates the RAD51-mediated homologous pairing in higher-ordered chromatin containing histone H1.

| S-EPMC4010968 | biostudies-literature

Efficient detection of unpaired DNA requires a member of the rad54-like family of homologous recombination proteins.

Project description:Meiotic silencing by unpaired DNA (MSUD) is a process that detects unpaired regions between homologous chromosomes and silences them for the duration of sexual development. While the phenomenon of MSUD is well recognized, the process that detects unpaired DNA is poorly understood. In this report, we provide two lines of evidence linking unpaired DNA detection to a physical search for DNA homology. First, we have found that a putative SNF2-family protein (SAD-6) is required for efficient MSUD in Neurospora crassa. SAD-6 is closely related to Rad54, a protein known to facilitate key steps in the repair of double-strand breaks by homologous recombination. Second, we have successfully masked unpaired DNA by placing identical transgenes at slightly different locations on homologous chromosomes. This masking falls apart when the distance between the transgenes is increased. We propose a model where unpaired DNA detection during MSUD is achieved through a spatially constrained search for DNA homology. The identity of SAD-6 as a Rad54 paralog suggests that this process may be similar to the searching mechanism used during homologous recombination.

| S-EPMC4224178 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data