Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

Transcriptional enhancers are brought into proximity with promoters via chromatin looping. The architectural transcription cofactor LDB1 facilitates spatial connectivity among enhancers and promoters, but whether this occurs through simple dimerization or requires heterotypic protein assemblies is unknown. Here, we investigated the role of single-stranded DNA-binding proteins (SSBPs) in regulating LDB1-mediated chromatin looping and transcription. SSBP2, SSBP3, and SSBP4 colocalize with LDB1 genome wide. Among these, only SSBP3 is essential for murine erythroid cell viability, LDB1 function, and transcription. LDB1, but not single-stranded DNA, is the predominant genome-wide tether of SSBP3 to chromatin. SSBP3 depletion in SSBP2/4 knockout cells globally weakened LDB1-dependent chromatin loops and lowered nascent transcription without impacting LDB1's chromatin binding. Chromatin tethering experiments revealed that SSBP3 and LDB1 mutually depend on each other to form looped contacts. SSBP3 stabilizes LDB1 dimerization in vitro, providing a possible mechanism. SSBPs emerge as key functional components of the architectural LDB1 complex.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC12402931PMC
http://dx.doi.org/10.1016/j.molcel.2025.07.012DOI Listing

Publication Analysis

Top Keywords

single-stranded dna-binding
8
dna-binding proteins
8
components architectural
8
ldb1
8
architectural ldb1
8
chromatin looping
8
chromatin
6
ssbp3
6
proteins essential
4
essential components
4

Similar Publications

Moss BRCA2 lacking the canonical DNA-binding domain promotes homologous recombination and binds to DNA.

Nucleic Acids Res

September 2025

Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin for Plant Sciences (IJPB), 78000 Versailles, France.

BRCA2 is crucial for mediating homology-directed DNA repair (HDR) through its binding to single-stranded DNA (ssDNA) and the recombinases RAD51 and DMC1. Most BRCA2 orthologs have a canonical DNA-binding domain (DBD) with the exception of Drosophila melanogaster. It remains unclear whether such a noncanonical BRCA2 variant without DBD possesses a DNA-binding activity.

View Article and Find Full Text PDF

DNA replication requires recruitment of Cdc45 and GINS into the MCM double hexamer by initiation factors to form an active helicase, the Cdc45-MCM-GINS (CMG) complex, at the replication origins. The initiation factor Sld3 is a central regulator of Cdc45 and GINS recruitment, working with Sld7 together. However, the mechanism through which Sld3 regulates CMG complex formation remains unclear.

View Article and Find Full Text PDF

Many adenovirus (AdV) species have been isolated from human and non-human primates. Here we describe the isolation of a new AdV from a western lowland gorilla held captive in a zoo. Analysis of the genome sequence demonstrated that this virus is a member of the Mastadenovirus genus, but markedly distinct from all previously described species.

View Article and Find Full Text PDF

Circular Rep-encoding single-stranded DNA (CRESS-DNA) virus Rep proteins are multidomain enzymes that mediate viral DNA rolling-circle replication. Reps nick viral DNA to expose a 3' end for polymerase extension, provide an NTP-dependent helicase activity for DNA unwinding, and join nicked ends to form circular viral genomes. Here, we present the first structures of a Rep protein from the family, a newly discovered family of human-associated CRESS-DNA viruses that replicates within the oral protozoan .

View Article and Find Full Text PDF

Thioflavin T Is a More General and Less Interfering Probe for Aptamer Binding Assays Than SYBR Green I.

Anal Chem

September 2025

Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.

Label-free fluorescent binding assays employing DNA staining dyes as probes are widely adopted techniques in the aptamer field. While many dyes have been used, thioflavin T (ThT) did not receive much attention for this purpose until recently, since it has long been perceived primarily as a G-quadruplex staining dye. Based on recent studies, ThT appears to serve as a reliable probe for evaluating the binding of non-G-quadruplex aptamers, and we seek to clarify the underlying mechanisms responsible for the exceptional performance of ThT.

View Article and Find Full Text PDF