H3K9 methylation (H3K9me) marks transcriptionally silent genomic regions called heterochromatin. HP1 proteins are required to establish and maintain heterochromatin. HP1 proteins bind to H3K9me, recruit factors that promote heterochromatin formation, and oligomerize to form phase-separated condensates. We do not understand how HP1 protein binding to heterochromatin establishes and maintains transcriptional silencing. Here, we demonstrate that the HP1 homolog, Swi6, can be completely bypassed to establish silencing at ectopic and endogenous loci when an H3K4 methyltransferase, Set1 and an H3K14 acetyltransferase, Mst2 are deleted. Deleting Set1 and Mst2 enhances Clr4 enzymatic activity, leading to higher H3K9me levels and spreading. In contrast, Swi6 and its capacity to oligomerize were indispensable during epigenetic maintenance. Our results demonstrate the role of HP1 proteins in regulating histone modification crosstalk during establishment and identifies a genetically separable function in maintaining epigenetic memory.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10634687PMC
http://dx.doi.org/10.1101/2023.04.30.538869DOI Listing

Publication Analysis

Top Keywords

hp1 proteins
16
heterochromatin hp1
8
hp1
6
heterochromatin
5
uncoupling distinct
4
distinct functions
4
functions hp1
4
proteins
4
proteins heterochromatin
4
heterochromatin establishment
4

Similar Publications

The recruitment of Heterochromatin Protein 1 (HP1) partners is essential for heterochromatin assembly and function, yet our knowledge regarding their organization in heterochromatin remains limited. Here we show that interactors engage the Drosophila HP1 (HP1a) dimer through a degenerate and expanded form of the previously identified PxVxL motif, which we now term HP1a Access Codes (HACs). These HACs reside in disordered regions, possess high conservation among Drosophila homologs, and contain alternating hydrophobic residues nested in a cluster of positively charged amino acids.

View Article and Find Full Text PDF

Novel role of zinc-finger protein 518 in heterochromatin formation on α-satellite DNA.

Nucleic Acids Res

December 2024

Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu 292-0818, Japan.

Aneuploidy is caused by chromosomal missegregation and is frequently observed in cancers and hematological diseases. Therefore, it is important to understand the molecular mechanisms underlying chromosomal segregation. The centromere's intricate structure is crucial for proper chromosome segregation, with heterochromatin at the pericentromeric α-satellites playing a key role.

View Article and Find Full Text PDF

In shrimp aquaculture, enhancing health and disease resistance is crucial for sustainable production. This study investigates the pioneering effects of astaxanthin-enriched microalgal powder from Haematococcus pluvialis (HP) on Pacific white shrimp (Litopenaeus vannamei), focusing on growth efficiency, body composition, immune and antioxidant responses, intestinal health, histopathology, gene expression, and resistance against Fusarium solani. Shrimp (initial weight 5.

View Article and Find Full Text PDF

Critical assessment of LC3/GABARAP ligands used for degrader development and ligandability of LC3/GABARAP binding pockets.

Nat Commun

November 2024

Institute for Pharmaceutical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt, Germany.

Recent successes in developing small molecule degraders that act through the ubiquitin system have spurred efforts to extend this technology to other mechanisms, including the autophagosomal-lysosomal pathway. Therefore, reports of autophagosome tethering compounds (ATTECs) have received considerable attention from the drug development community. ATTECs are based on the recruitment of targets to LC3/GABARAP, a family of ubiquitin-like proteins that presumably bind to the autophagosome membrane and tether cargo-loaded autophagy receptors into the autophagosome.

View Article and Find Full Text PDF

Prions represent epigenetic regulator proteins that can self-propagate their structure and confer their misfolded structure and function on normally folded proteins. Like the mammalian prion PrPSc, prions also occur in fungi. While a few prions, like Swi1, affect gene expression, none are shown to affect heterochromatin structure and function.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!