Structure, Activity and Function of the NSD3 Protein Lysine Methyltransferase

High Expression of ZFP42 Improves Early Development of Pig Embryos Produced by Handmade Cloning

Handmade Cloning (HMC) is a pivotal technique for cloning pig embryos. Despite its significance, the low efficiency of this method hampers its widespread application. Although numerous factors and signaling pathways influencing embryo development have been studied, the mechanisms underlying low developmental capacity and insufficient reprogramming of cloned embryos remain elusive. In the present study, we sought to elucidate key regulatory factors involved in the development of pig HMC embryos by comparing and analyzing the gene expression profiles of HMC embryos with those of naturally fertilized (NF) embryos at the 4-cell, 8-cell, and 16-cell stages. The results showed that ZFP42 expression is markedly higher in NF embryos than in cloned counterparts. Subsequent experiments involving the injection of ZFP42 messenger RNA (mRNA) into HMC embryos showed that ZFP42 could enhance the blastocyst formation rate, upregulate pluripotent genes and metabolic pathways. This highlights the potential of ZFP42 as a critical factor in improving the development of pig HMC embryos.

WHSC1L1-mediated epigenetic downregulation of VMP1 participates in herpes simplex virus 1 infection-induced mitophagy impairment and neuroinflammation

Microglia are the first-line defenders against invading pathogens in the brain whose activation mediates virus clearance and leads to neurotoxicity as well. This work studies the role of Wolf-Hirschhorn syndrome candidate 1-like 1 (WHSC1L1)/vacuole membrane protein 1 (VMP1) interaction in the activation of microglia and neuroinflammation following herpes simplex virus 1 (HSV-1) infection. Aberrantly expressed genes after HSV-1 infection were screened by analyzing the GSE35943 dataset. C57BL/6J mice and mouse microglia BV2 were infected with HSV-1 for in vivo and in vitro assays. VMP1 was downregulated but WHSC1L1 was upregulated in HSV-1-infected mouse brain tissues as well as in BV2 cells. The VMP1 overexpression enhanced mitophagy activity and suppressed oxidative stress and inflammatory activation of BV2 cells, but these effects were blocked by the autophagy antagonist 3-methyladenine. WHSC1H1 suppressed VMP1 transcription through H3K36me2-recruited DNMT3A. Downregulation of WHSC1H1 similarly enhanced mitophagy in BV2 cells, and it alleviated microglia activation, nerve cell inflammation, and brain tissue damage in HSV-1-infected mice. However, the alleviating roles of WHSC1H1 silencing were negated by further VMP1 silencing. Taken together. this study demonstrates that WHSC1L1 upregulation following HSV-1 infection leads to mitophagy impairment and neuroinflammation through epigenetic suppression of VMP1.

Nizp1 is a specific NUP98 ‐ NSD1 functional interactor that regulates NUP98 ‐ NSD1 ‐dependent oncogenic programs

NSD1, NSD2 and NSD3 proteins constitute a family of histone 3 lysine 36 (H3K36) methyltransferases with similar domain architecture, but diversified activities, in part, dependent on their non-enzymatic domains. These domains, despite their high sequence identity, recruit the hosting proteins to different chromatin regions through the recognition of diverse epigenetic marks and/or associations to distinct interactors. In this sense, the PHDvC5HCH finger tandem domain represents a paradigmatic example of functional divergence within the NSD family. In this work, we prove and give a structural rationale for the uniqueness of the PHDvC5HCH domain of NSD1 in recognizing the C2HR Zinc finger domain of Nizp1 (NSD1 interacting Zn finger protein). Importantly, we show that, in a leukaemogenic context, Nizp1 is pivotal in driving the unscheduled expression of HoxA genes and of genes involved in the type I IFN pathway, triggered by the expression of the fusion protein NUP98-NSD1. These data provide the first insight into the pathophysiological relevance of the Nizp1-NSD1 functional association. Targeting of this interaction might open new therapeutic windows to inhibit the NUP98-NSD1 oncogenic properties.

PROTACs: great opportunities for academia and industry (an update from 2020 to 2021)

PROteolysis TArgeting Chimeras (PROTACs) technology is a new protein-degradation strategy that has emerged in recent years. It uses bifunctional small molecules to induce the ubiquitination and degradation of target proteins through the ubiquitin–proteasome system. PROTACs can not only be used as potential clinical treatments for diseases such as cancer, immune disorders, viral infections, and neurodegenerative diseases, but also provide unique chemical knockdown tools for biological research in a catalytic, reversible, and rapid manner. In 2019, our group published a review article “PROTACs: great opportunities for academia and industry” in the journal, summarizing the representative compounds of PROTACs reported before the end of 2019. In the past 2 years, the entire field of protein degradation has experienced rapid development, including not only a large increase in the number of research papers on protein-degradation technology but also a rapid increase in the number of small-molecule degraders that have entered the clinical and will enter the clinical stage. In addition to PROTAC and molecular glue technology, other new degradation technologies are also developing rapidly. In this article, we mainly summarize and review the representative PROTACs of related targets published in 2020–2021 to present to researchers the exciting developments in the field of protein degradation. The problems that need to be solved in this field will also be briefly introduced.