KEOPS complex promotes homologous recombination via DNA resection

Abstract

KEOPS complex is one of the most conserved protein complexes in eukaryotes. It plays important roles in both telomere uncapping and tRNA N 6 -threonylcarbamoyladenosine (t 6 A) modification in budding yeast. But whether KEOPS complex plays any roles in DNA repair remains unknown. Here, we show that KEOPS complex plays positive roles in both DNA damage response and homologous recombination-mediated DNA repair independently of its t 6 A synthesis function. Additionally, KEOPS displays DNA binding activity in vitro , and is recruited to the chromatin at DNA breaks in vivo , suggesting a direct role of KEOPS in DSB repair. Mechanistically, KEOPS complex appears to promote DNA end resection through facilitating the association of Exo1 and Dna2 with DNA breaks. Interestingly, inactivation of both KEOPS and Mre11/Rad50/Xrs2 (MRX) complexes results in synergistic defect in DNA resection, revealing that KEOPS and MRX have some redundant functions in DNA resection. Thus we uncover a t 6 A-independent role of KEOPS complex in DNA resection, and propose that KEOPS might be a DSB sensor to assist cells in maintaining chromosome stability.

MEIS2 Is an Adrenergic Core Regulatory Transcription Factor Involved in Early Initiation of TH-MYCN-Driven Neuroblastoma Formation

“…To this end, we compared transcriptomes from week 1 versus 2 and 6 and identified a total of 377 significantly differentially expressed genes in TH-MYCN +/+ versus wild-type mice (absolute log 2 fold change threshold of 1 and adjusted p < 0.01, top-100 shown in Figure 4 A). The strongest upregulated gene in the latter analysis is gm6890 , a homolog of the human LAGE3 gene and encodes for a protein that is part of the strongly evolutionary conserved “Kinase, Endopeptidase and Other Proteins of Small size” (KEOPS) complex implicated in t6A tRNA biosynthesis [ 51 ], homologous double-strand break repair and telomere maintenance [ 52 , 53 ]. We also scored these signatures in a large cohort of primary neuroblastoma tumor samples (GSE120572).…”

Swc4 positively regulates telomere length independently of its roles in NuA4 and SWR1 complexes

“…In order to validate the direct role of Swc4 at telomeres, we performed chromatin immune-precipitation assay. The chromatin in the cells expressing Swc4 13myc and non-tagged cells was cross-linked and sonicated ( 40 ). Monoclonal anti-myc antibody was used to precipitate Swc4 13myc -associated chromatin, and precipitated DNA was purified and examined by dot-blotting with a telomeric C 1–3 A probe.…”

“…Yeast cells (MATa) grown to mid-log phase were synchronized at G1 phase by adding 10 ug/ml α-factor (incubated at 30°C for 2 h, every 40 min replenished 5 ug/ml α-factor), and released into S and G2/M phases at 24°C. FACS assay was performed as previously decribed ( 40 ).…”

“…ChIP assay was performed as previously described, with following modifications ( 40 ). Immunoprecipitation of cross-linked DNA was probed by monoclonal anti-c-Myc antibody (Sigma-Aldrich: M4439).…”

Structure of a reaction intermediate mimic in t6A biosynthesis bound in the active site of the TsaBD heterodimer from Escherichia coli

“…KEOPS was originally identified as a transcription complex ( 20 ) involved in telomere regulation ( 21 ). In addition to its requirement for t 6 A tRNA modification, KEOPS proteins in yeast have t 6 A-independent roles in telomere replication via SUA5p ( 22 ) and as an auxiliary sensor of DNA double strand breaks ( 23 ). KEOPS mutations have been recently implicated in neurodegeneration with nephrotic disease in humans ( 24–26 ).…”