2024年8月28日 · Instead, HP1α foci appear to be the result of more HP1α dimer bridged nucleosomes and chromatin fibres occupying these sub-micron spaces, alongside HP1α monomers that impart a global nucleosome spacing throughout live cell chromatin. HP1α monomers bind chromatin, and this interaction depends on H3K9me3 recognition

2023年10月23日 · We show that Drosophila HP1a protein undergoes liq.-liq. demixing in vitro, and nucleates into foci that display liq. properties during the first stages of heterochromatin domain formation in early Drosophila embryos.

The binding mode of HP1 dimer to nucleosome (Swi6 of fission yeast) in this model involves multivalent interactions mediated by H3K9me3-CD, nucleosomal DNA-HR, and H2B-CSD dimer.

2018年2月1日 · Here we report the three-dimensional structure of the H3K9me3-containing dinucleosomes complexed with human HP1α, HP1β, and HP1γ, determined by cryogenic electron microscopy with a Volta phase plate. In the structures, two H3K9me3 nucleosomes are bridged by a symmetric HP1 dimer.

2024年10月8日 · Here, we present the cryoelectron microscopy (cryo-EM) structure of an HP1a dimer bound to an H2A.Z-nucleosome, revealing two distinct HP1 -nucleosome interfaces. The pri- 9 (K9me3) region, while a secondary binding site is situated near histone H2B, close to nucleosome super-helical location 4 (SHL4).

2021年6月9日 · Further experiments with dimerization-deficient HP1α I165E indicate that chromatin crosslinking via HP1α dimerization is critical, while polymer simulations demonstrate the importance of chromatin-chromatin crosslinkers in mechanics.

2021年3月4日 · In mammals, HP1-mediated heterochromatin forms positionally and mechanically stable genomic domains even though the component HP1 paralogs, HP1α, HP1β, and HP1γ, display rapid on-off dynamics. Here, we investigate whether phase-separation by HP1 proteins can explain these biological observations.

2017年6月21日 · The shugoshin 1 (Sgo1) and lamin B receptor (LBR) proteins have been shown to interact directly with the CSD dimer of HP1α via a specific PXXVXL-like sequence in shugoshin, and a...

2013年8月2日 · Drosophila melanogaster Heterochromatin Protein 1a (HP1a) is an essential protein critical for heterochromatin assembly and regulation. Its chromo shadow domain (CSD) homodimerizes, a requirement for binding protein partners that contain a PXVXL motif. How does HP1a select among its many different PXVXL-containing partners?

2022年12月9日 · In vitro, HP1α can undergo phase separation upon phosphorylation of its N-terminus extension (NTE) and/or through interactions with DNA and chromatin. Here, we combine computational and experimental approaches to elucidate the molecular interactions that drive these processes.