Homeostatic synaptic downscaling reduces neuronal excitability by modulating the number of postsynaptic receptors. Histone modifications and the subsequent chromatin remodeling play critical roles in activity-dependent gene expression. Histone modification codes are recognized by chromatin readers that affect gene expression by altering chromatin structure. We show that L3mbtl1 (lethal 3 malignant brain tumor-like 1), a polycomb chromatin reader, is downregulated by neuronal activity and is essential for synaptic response and downscaling. Genome-scale mapping of L3mbtl1 occupancies identified Ctnnb1 as a key gene downstream of L3mbtl1. Importantly, the occupancy of L3mbtl1 on the Ctnnb1 gene was regulated by neuronal activity. L3mbtl1 knockout neurons exhibited reduced Ctnnb1 expression. Partial knockdown of Ctnnb1 in wild-type neurons reduced excitatory synaptic transmission and abolished homeostatic downscaling, and transfecting Ctnnb1 in L3mbtl1 knockout neurons enhanced synaptic transmission and restored homeostatic downscaling. These results highlight a role for L3mbtl1 in regulating homeostasis of synaptic efficacy.
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http://dx.doi.org/10.1016/j.celrep.2018.05.028 | DOI Listing |
Cell Rep
January 2025
Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address:
Chromatin regulatory proteins are expressed broadly and assumed to exert the same intrinsic function across cell types. Here, we report that 14 chromatin regulators undergo evolutionary-conserved neuron-specific splicing events involving microexons. Among them are two components of a histone demethylase complex: LSD1 H3K4 demethylase and the H3K4me0-reader PHF21A.
View Article and Find Full Text PDFEMBO J
January 2025
Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria.
J Biomed Sci
January 2025
Key Laboratory of Molecular Epigenetics of Ministry of Education, College of Life Sciences, Northeast Normal University, Changchun, 130024, China.
ROS cause multiple forms of DNA damage, and among them, 8-oxoguanine (8-oxoGua), an oxidized product of guanine, is one of the most abundant. If left unrepaired, 8-oxoGua may pair with A instead of C, leading to a mutation of G: C to T: A during DNA replication. 8-Oxoguanine DNA glycosylase 1 (OGG1) is a tailored repair enzyme that recognizes 8-oxoGua in DNA duplex and initiates the base excision repair (BER) pathway to remove the lesion and ensure the fidelity of the genome.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Department of General Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
Poor response to 5-fluorouracil (5-FU) remains an obstacle in the treatment of gastric cancer (GC). Super enhancers (SEs) are crucial for determining tumor cell survival under drug pressure. SE landscapes related to 5-FU-resistance are mapped to GC using chromatin immunoprecipitation-sequencing (ChIP-Seq).
View Article and Find Full Text PDFCell Rep
December 2024
Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
A significant portion of human cancers utilize a recombination-based pathway, alternative lengthening of telomeres (ALT), to extend telomeres. To gain further insights into this pathway, we developed a high-throughput imaging-based screen named TAILS (telomeric ALT in situ localization screen) to identify genes that either promote or inhibit ALT activity. Screening over 1,000 genes implicated in DNA transactions, TAILS reveals both well-established and putative ALT modulators.
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