RECQ1 interacts with FEN-1 and promotes binding of FEN-1 to telomeric chromatin

Sami, Furqan; Lu, Xing; Parvathaneni, Swetha; Roy, Rabindra; Gary, Ronald K.; Sharma, Sudha

doi:10.1042/bj20141021

Cited by 18 publications

(16 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably, RECQ1-C453A, RECQ1-C475A, and RECQ1-C478A mutants failed to unwind fork duplex and no detectable unwinding of the fork duplex was observed even at the excessively increased protein concentration (160 nM) (Figure 2A and 2B). Consistent with their inability to unwind fork duplex, RECQ1 variants RECQ1-C453A, RECQ1-C475A and RECQ1-C478A failed to unwind a 5’-flap substrate that mimics intermediate of DNA replication and repair and is unwound by wild-type RECQ1 [21,36]. In a control reaction and as previously reported [21], RECQ1 protein containing a K119A mutation within the helicase domain also failed to unwind 5’-flap DNA substrate.…”

Section: Resultssupporting

confidence: 70%

See 1 more Smart Citation

Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain

Sami

Gary

Fang

et al. 2016

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

Self Cite

View full text Add to dashboard Cite

RecQ helicases are a highly conserved family of ATP-dependent DNA-unwinding enzymes with key roles in DNA replication and repair in all kingdoms of life. The RECQ1 gene encodes the most abundant RecQ homolog in humans. Mutations in RECQ1 significantly increase breast cancer susceptibility. We engineered full-length RECQ1 harboring point mutations in the zinc-binding motif (amino acids 419–480) within the conserved RecQ-specific-C-terminal (RQC) domain known to be critical for diverse biochemical and cellular functions of RecQ helicases. Wild-type RECQ1 contains a zinc ion. Substitution of three of the four conserved cysteine residues that coordinate zinc severely impaired the ATPase and DNA unwinding activities but retained DNA binding and single strand DNA annealing activities. Furthermore, alteration of these residues attenuated zinc binding and significantly changed the overall conformation of full-length RECQ1 protein. In contrast, substitution of cysteine residue at position 471 resulted in a wild-type like RECQ1 protein. Differential contribution of the conserved cysteine residues to the structure and functions of the RECQ1 protein is also inferred by homology modeling. Overall, our results indicate that the zinc binding motif in the RQC domain of RECQ1 is a key structural element that is essential for the structure-functions of RECQ1. Given the recent association of RECQ1 mutations with breast cancer, these observations will contribute to understanding the molecular basis of RECQ1 functions in cancer etiology.

show abstract

Section: Resultssupporting

confidence: 70%

“…Full-length RECQ1 proteins, wild-type (RECQ1-WT) or with engineered single amino acid substitutions with alanine at conserved cysteine residues (RECQ1-C453A, RECQ1-C471A, RECQ1-C475A, and RECQ1-C478A) were overexpressed in bacteria and purified to near homogeneity using a previously reported method [25,36]. …”

Section: Resultsmentioning

confidence: 99%

Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain

Sami

Gary

Fang

et al. 2016

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

Self Cite

View full text Add to dashboard Cite

show abstract

“…Besides, yeast two-hybrid assays identified potential homo-and hetero-typical interactions between different P. falciparum ApiAP2 proteins as well as interaction with other P. falciparum transcriptional regulators (LaCount et al, 2005). (Sami et al, 2015). (Sami et al, 2015).…”

Section: Pfap2tel Is a Nuclear Protein That Co-localises With Telommentioning

confidence: 99%

“…The nuclear protein complex that binds to P. falciparum telomeres, in addition to PfAP2Tel, contains proteins with DNA helicase and endonuclease activities, DNA mismatch repair activity, zinc finger domains and bromodomains ( (Sami et al, 2015).…”

Section: Pfap2tel Is a Nuclear Protein That Co-localises With Telommentioning

confidence: 99%

PfAP2Tel, harbouring a non-canonical DNA-binding AP2 domain, binds toPlasmodium falciparumtelomeres

Sierra-Miranda¹,

Vembar

Delgadillo³

et al. 2017

Cellular Microbiology

View full text Add to dashboard Cite

The telomeres of the malaria parasite Plasmodium falciparum are essential not only for chromosome end maintenance during blood stage development in humans but also to generate genetic diversity by facilitating homologous recombination of subtelomeric, multigene virulence families such as var and rifin. However, other than the telomerase PfTERT, proteins that act at P. falciparum telomeres are poorly characterised. To isolate components that bind to telomeres, we performed oligonucleotide pulldowns and electromobility shift assays with a telomeric DNA probe and identified a non-canonical member of the ApiAP2 family of transcription factors, PfAP2Tel (encoded by PF3D7_0622900), as a component of the P. falciparum telomere-binding protein complex. PfAP2Tel is expressed throughout the intra-erythrocytic life cycle and localises to the nuclear periphery, co-localising with telomeric clusters. Furthermore, EMSAs using the recombinant protein demonstrated direct binding of PfAP2Tel to telomeric repeats in vitro, while genome-wide chromatin immunoprecipitation followed by next generation sequencing corroborated the high specificity of this protein to telomeric ends of all 14 chromosomes in vivo. Taken together, our data describe a novel function for ApiAP2 proteins at chromosome ends and open new avenues to study the molecular machinery that regulates telomere function in P. falciparum.

show abstract

“…Subsequent studies elucidated that RECQ1 helicase is a major player in maintaining replication fork progression under stress [9–12]. We have found that RECQ1 is enriched at specific genomic regions that pose significant challenge to replication and transcription, and are hotspots for instability and mutagenesis in cancer [12,13]. We reasoned that RECQ1 could be a multifunctional protein due to its high abundance and specific interactions with chromatin.…”

Section: Introductionmentioning

confidence: 99%

Transcriptome guided identification of novel functions of RECQ1 helicase

Parvathaneni

et al. 2016

Methods

Self Cite

View full text Add to dashboard Cite

Gene expression changes in the functional absence of a specific RecQ protein, and how that relates to disease outcomes including cancer predisposition and premature aging in RecQ helicase associated syndromes, are poorly understood. Here we describe detailed experimental strategy for identification of RECQ1-regulated transcriptome that led us to uncover a novel association of RECQ1 in regulation of cancer cell migration and invasion. We initiated a focused study to determine whether RECQ1, the most abundant RecQ protein in humans, alters gene expression and also investigated whether RECQ1 binds with G4 motifs predicted to form G-quadruplex structures in the target gene promoters. Rescue of mRNA expression of select RECQ1-downregulated genes harboring G4 motifs required wild-type RECQ1 helicase. However, some RECQ1-regulated genes are also regulated by BLM and WRN proteins regardless of the presence or absence of G4 motifs. The approach described here is applicable for systematic comparison of gene expression signatures of individual RecQ proteins in isogenic background, and to elucidate their participation in transcription regulation through G-quadruplex recognition and/or resolution. Such strategies might also reveal molecular pathways that drive the pathogenesis of cancer and other diseases in specific RecQ deficiency.

show abstract

RECQ1 interacts with FEN-1 and promotes binding of FEN-1 to telomeric chromatin

Cited by 18 publications

References 78 publications

Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain

Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain

PfAP2Tel, harbouring a non-canonical DNA-binding AP2 domain, binds toPlasmodium falciparumtelomeres

Transcriptome guided identification of novel functions of RECQ1 helicase

Contact Info

Product

Resources

About