Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Regulation of Rad51 function by phosphorylation.

ABSTRACT: Rad51 is a key enzyme involved in DNA double-strand break repair by homologous recombination. Here, we show that in response to DNA damage, budding yeast Rad51 is phosphorylated on Ser 192 in a manner that is primarily mediated by the DNA-damage-responsive protein kinase Mec1. We show that mutating Rad51 Ser 192 to Ala or Glu confers hypersensitivity to DNA damage and homologous-recombination defects. Furthermore, biochemical analyses indicate that Ser 192 is required for Rad51 adenosine triphosphate hydrolysis and DNA-binding activity in vitro, whereas mutation of Ser 192 does not interfere with Rad51 multimer formation. These data suggest a model in which Mec1-mediated phosphorylation of Rad51 Ser 192 in response to DNA damage controls Rad51 activity and DNA repair by homologous recombination.

SUBMITTER: Flott S

PROVIDER: S-EPMC3147262 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Regulation of Rad51 function by phosphorylation.

Flott Sonja S Kwon Youngho Y Pigli Ying Zhang YZ Rice Phoebe A PA Sung Patrick P Jackson Stephen P SP

EMBO reports 20110708 8

Rad51 is a key enzyme involved in DNA double-strand break repair by homologous recombination. Here, we show that in response to DNA damage, budding yeast Rad51 is phosphorylated on Ser 192 in a manner that is primarily mediated by the DNA-damage-responsive protein kinase Mec1. We show that mutating Rad51 Ser 192 to Ala or Glu confers hypersensitivity to DNA damage and homologous-recombination defects. Furthermore, biochemical analyses indicate that Ser 192 is required for Rad51 adenosine triphos ...[more]

PMID: 21738226

Similar Datasets

ATM/ATR-mediated phosphorylation of PALB2 promotes RAD51 function.

Project description:DNA damage activates the ATM and ATR kinases that coordinate checkpoint and DNA repair pathways. An essential step in homology-directed repair (HDR) of DNA breaks is the formation of RAD51 nucleofilaments mediated by PALB2-BRCA2; however, roles of ATM and ATR in this critical step of HDR are poorly understood. Here, we show that PALB2 is markedly phosphorylated in response to genotoxic stresses such as ionizing radiation and hydroxyurea. This response is mediated by the ATM and ATR kinases through three N-terminal S/Q-sites in PALB2, the consensus target sites for ATM and ATR Importantly, a phospho-deficient PALB2 mutant is unable to support proper RAD51 foci formation, a key PALB2 regulated repair event, whereas a phospho-mimicking PALB2 version supports RAD51 foci formation. Moreover, phospho-deficient PALB2 is less potent in HDR than wild-type PALB2. Further, this mutation reveals a separation in PALB2 function, as the PALB2-dependent checkpoint response is normal in cells expressing the phospho-deficient PALB2 mutant. Collectively, our findings highlight a critical importance of PALB2 phosphorylation as a novel regulatory step in genome maintenance after genotoxic stress.

| S-EPMC5341514 | biostudies-literature

CDK phosphorylation of Sfr1 downregulates Rad51 function in late-meiotic homolog invasions

Project description:Meiosis is the developmental program that generates gametes. To produce healthy gametes, meiotic recombination creates reciprocal exchanges between each pair of homologous chromosomes that facilitate faithful chromosome segregation. Using fission yeast and biochemical, genetic, and cytological approaches, we have studied the role of CDK (Cyclin-Dependent Kinase) in the control of Swi5-Sfr1, a Rad51-recombinase auxiliary factor involved in homolog invasion during recombination. We show that Sfr1 is a CDK target, and its phosphorylation downregulates Swi5-Sfr1 function in meiotic prophase. Expression of a phospho-mimetic sfr1-7D mutant inhibits Rad51 binding, its robust chromosome loading, and subsequently decreases interhomolog recombination. On the other hand, the non-phosphorylatable sfr1-7A mutant alters Rad51 dynamics at late prophase, and exacerbates chromatin segregation defects and Rad51 retention observed in dbl2 deletion mutants when combined with them. We propose Sfr1 phospho-inhibition as a novel cell-cycle-dependent mechanism, which ensures timely resolution of recombination intermediates and successful chromosome distribution into the gametes. Furthermore, the N-terminal disordered part of Sfr1, an evolutionarily conserved feature, serves as a regulatory platform coordinating this phospho-regulation, protein localization and stability, with several CDK sites and regulatory sequences being conserved.

| S-SCDT-10_1038-S44318-024-00205-2 | biostudies-other

Regulation of OATP1B1 Function by Tyrosine Kinase-mediated Phosphorylation.

Project description:PurposeOATP1B1 (SLCO1B1) is the most abundant and pharmacologically relevant uptake transporter in the liver and a key mediator of xenobiotic clearance. However, the regulatory mechanisms that determine OATP1B1 activity remain uncertain, and as a result, unexpected drug-drug interactions involving OATP1B1 substrates continue to be reported, including several involving tyrosine kinase inhibitors (TKI).Experimental designOATP1B1-mediated activity in overexpressing HEK293 cells and hepatocytes was assessed in the presence of FDA-approved TKIs, while rosuvastatin pharmacokinetics in the presence of an OATP1B1 inhibiting TKI were measured in vivo. Tyrosine phosphorylation of OATP1B1 was determined by LC/MS-MS-based proteomics and transport function was measured following exposure to siRNAs targeting 779 different kinases.ResultsTwenty-nine of 46 FDA-approved TKIs studied significantly inhibit OATP1B1 function. Inhibition of OATP1B1 by TKIs, such as nilotinib, is predominantly noncompetitive, can increase systemic concentrations of rosuvastatin in vivo, and is associated with reduced phosphorylation of OATP1B1 at tyrosine residue 645. Using genetic screens and functional validation studies, the Src kinase LYN was identified as a potential regulator of OATP1B1 activity that is highly sensitive to inhibition by various TKIs at clinically relevant concentrations.ConclusionsA novel kinase-dependent posttranslational mechanism of OATP1B1 activation was identified and interference with this process by TKIs can influence the elimination of a broad range of xenobiotic substrates.

| S-EPMC8358987 | biostudies-literature

Nucleotide proofreading functions by nematode RAD51 paralogs facilitate optimal RAD51 filament function.

Project description:The RAD51 recombinase assembles as helical nucleoprotein filaments on single-stranded DNA (ssDNA) and mediates invasion and strand exchange with homologous duplex DNA (dsDNA) during homologous recombination (HR), as well as protection and restart of stalled replication forks. Strand invasion by RAD51-ssDNA complexes depends on ATP binding. However, RAD51 can bind ssDNA in non-productive ADP-bound or nucleotide-free states, and ATP-RAD51-ssDNA complexes hydrolyse ATP over time. Here, we define unappreciated mechanisms by which the RAD51 paralog complex RFS-1/RIP-1 limits the accumulation of RAD-51-ssDNA complexes with unfavorable nucleotide content. We find RAD51 paralogs promote the turnover of ADP-bound RAD-51 from ssDNA, in striking contrast to their ability to stabilize productive ATP-bound RAD-51 nucleoprotein filaments. In addition, RFS-1/RIP-1 inhibits binding of nucleotide-free RAD-51 to ssDNA. We propose that 'nucleotide proofreading' activities of RAD51 paralogs co-operate to ensure the enrichment of active, ATP-bound RAD-51 filaments on ssDNA to promote HR.

| S-EPMC8452638 | biostudies-literature

Regulation and pharmacological targeting of RAD51 in cancer.

Project description:Regulation of homologous recombination (HR) is central for cancer prevention. However, too little HR can increase cancer incidence, whereas too much HR can drive cancer resistance to therapy. Importantly, therapeutics targeting HR deficiency have demonstrated a profound efficacy in the clinic improving patient outcomes, particularly for breast and ovarian cancer. RAD51 is central to DNA damage repair in the HR pathway. As such, understanding the function and regulation of RAD51 is essential for cancer biology. This review will focus on the role of RAD51 in cancer and beyond and how modulation of its function can be exploited as a cancer therapeutic.

| S-EPMC7520849 | biostudies-literature

Developmental Regulation of KCC2 Phosphorylation Has Long-Term Impacts on Cognitive Function.

Project description:GABAA receptor-mediated currents shift from excitatory to inhibitory during postnatal brain development in rodents. A postnatal increase in KCC2 protein expression is considered to be the sole mechanism controlling the developmental onset of hyperpolarizing synaptic transmission, but here we identify a key role for KCC2 phosphorylation in the developmental EGABA shift. Preventing phosphorylation of KCC2 in vivo at either residue serine 940 (S940), or at residues threonine 906 and threonine 1007 (T906/T1007), delayed or accelerated the postnatal onset of KCC2 function, respectively. Several models of neurodevelopmental disorders including Rett syndrome, Fragile × and Down's syndrome exhibit delayed postnatal onset of hyperpolarizing GABAergic inhibition, but whether the timing of the onset of hyperpolarizing synaptic inhibition during development plays a role in establishing adulthood cognitive function is unknown; we have used the distinct KCC2-S940A and KCC2-T906A/T1007A knock-in mouse models to address this issue. Altering KCC2 function resulted in long-term abnormalities in social behavior and memory retention. Tight regulation of KCC2 phosphorylation is therefore required for the typical timing of the developmental onset of hyperpolarizing synaptic inhibition, and it plays a fundamental role in the regulation of adulthood cognitive function.

| S-EPMC6664008 | biostudies-literature

<i>RAD51</i> Gene Family Structure and Function.

Project description:Accurate DNA repair and replication are critical for genomic stability and cancer prevention. RAD51 and its gene family are key regulators of DNA fidelity through diverse roles in double-strand break repair, replication stress, and meiosis. RAD51 is an ATPase that forms a nucleoprotein filament on single-stranded DNA. RAD51 has the function of finding and invading homologous DNA sequences to enable accurate and timely DNA repair. Its paralogs, which arose from ancient gene duplications of RAD51, have evolved to regulate and promote RAD51 function. Underscoring its importance, misregulation of RAD51, and its paralogs, is associated with diseases such as cancer and Fanconi anemia. In this review, we focus on the mammalian RAD51 structure and function and highlight the use of model systems to enable mechanistic understanding of RAD51 cellular roles. We also discuss how misregulation of the RAD51 gene family members contributes to disease and consider new approaches to pharmacologically inhibit RAD51.

| S-EPMC7703940 | biostudies-literature

TOPBP1 regulates RAD51 phosphorylation and chromatin loading and determines PARP inhibitor sensitivity.

Project description:Topoisomerase IIβ-binding protein 1 (TOPBP1) participates in DNA replication and DNA damage response; however, its role in DNA repair and relevance for human cancer remain unclear. Here, through an unbiased small interfering RNA screen, we identified and validated TOPBP1 as a novel determinant whose loss sensitized human cells to olaparib, an inhibitor of poly(ADP-ribose) polymerase. We show that TOPBP1 acts in homologous recombination (HR) repair, impacts olaparib response, and exhibits aberrant patterns in subsets of human ovarian carcinomas. TOPBP1 depletion abrogated RAD51 loading to chromatin and formation of RAD51 foci, but without affecting the upstream HR steps of DNA end resection and RPA loading. Furthermore, TOPBP1 BRCT domains 7/8 are essential for RAD51 foci formation. Mechanistically, TOPBP1 physically binds PLK1 and promotes PLK1 kinase-mediated phosphorylation of RAD51 at serine 14, a modification required for RAD51 recruitment to chromatin. Overall, our results provide mechanistic insights into TOPBP1's role in HR, with potential clinical implications for cancer treatment.

| S-EPMC4748576 | biostudies-literature

Mek1 Down Regulates Rad51 Activity during Yeast Meiosis by Phosphorylation of Hed1.

Project description:During meiosis, programmed double strand breaks (DSBs) are repaired preferentially between homologs to generate crossovers that promote proper chromosome segregation at Meiosis I. In many organisms, there are two strand exchange proteins, Rad51 and the meiosis-specific Dmc1, required for interhomolog (IH) bias. This bias requires the presence, but not the strand exchange activity of Rad51, while Dmc1 is responsible for the bulk of meiotic recombination. How these activities are regulated is less well established. In dmc1Δ mutants, Rad51 is actively inhibited, thereby resulting in prophase arrest due to unrepaired DSBs triggering the meiotic recombination checkpoint. This inhibition is dependent upon the meiosis-specific kinase Mek1 and occurs through two different mechanisms that prevent complex formation with the Rad51 accessory factor Rad54: (i) phosphorylation of Rad54 by Mek1 and (ii) binding of Rad51 by the meiosis-specific protein Hed1. An open question has been why inhibition of Mek1 affects Hed1 repression of Rad51. This work shows that Hed1 is a direct substrate of Mek1. Phosphorylation of Hed1 at threonine 40 helps suppress Rad51 activity in dmc1Δ mutants by promoting Hed1 protein stability. Rad51-mediated recombination occurring in the absence of Hed1 phosphorylation results in a significant increase in non-exchange chromosomes despite wild-type levels of crossovers, confirming previous results indicating a defect in crossover assurance. We propose that Rad51 function in meiosis is regulated in part by the coordinated phosphorylation of Rad54 and Hed1 by Mek1.

| S-EPMC4970670 | biostudies-literature

A phosphorylation-deubiquitination cascade regulates the BRCA2-RAD51 axis in homologous recombination.

Project description:Homologous recombination (HR) is one of the major DNA double-strand break (DSB) repair pathways in mammalian cells. Defects in HR trigger genomic instability and result in cancer predisposition. The defining step of HR is homologous strand exchange directed by the protein RAD51, which is recruited to DSBs by BRCA2. However, the regulation of the BRCA2-RAD51 axis remains unclear. Here we report that ubiquitination of RAD51 hinders RAD51-BRCA2 interaction, while deubiquitination of RAD51 facilitates RAD51-BRCA2 binding and RAD51 recruitment and thus is critical for proper HR. Mechanistically, in response to DNA damage, the deubiquitinase UCHL3 is phosphorylated and activated by ATM. UCHL3, in turn, deubiquitinates RAD51 and promotes the binding between RAD51 and BRCA2. Overexpression of UCHL3 renders breast cancer cells resistant to radiation and chemotherapy, while depletion of UCHL3 sensitizes cells to these treatments, suggesting a determinant role of UCHL3 in cancer therapy. Overall, we identify UCHL3 as a novel regulator of DNA repair and reveal a model in which a phosphorylation-deubiquitination cascade dynamically regulates the BRCA2-RAD51 pathway.

| S-EPMC5204351 | 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