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The synthesis of membrane and secreted proteins is safeguarded by an endoplasmic reticulum-associated ribosome quality control (ER-RQC) that promotes the disposal of defective translation products by the proteasome or via a lysosome-dependent pathway involving the degradation of portions of the ER by macroautophagy (reticulophagy). The UFMylation of RPL26 on ER-stalled ribosomes is essential for activating the ER-RQC and reticulophagy. Here, we report that the viral deubiquitinase (vDUB) encoded in the N-terminal domain of the Epstein-Barr virus (EBV) large tegument protein BPLF1 hinders the UFMylation of RPL26 on ribosomes that stall at the ER, promotes the stabilization of ER-RQC substrates, and inhibits reticulophagy. The vDUB did not act as a de-UFMylase or interfere with the UFMylation of the ER membrane protein CYB5R3 by the UFL1 ligase. Instead, it copurified with ribosomes in sucrose gradients and abrogated a ZNF598- and LTN1-independent ubiquitination event required for RPL26 UFMylation. Physiological levels of BPLF1 impaired the UFMylation of RPL26 in productively EBV-infected cells, pointing to an important role of the enzyme in regulating the translation quality control that allows the efficient synthesis of viral proteins and the production of infectious virus. Abbreviation : BPLF1, BamH1 P fragment left open readingframe-1; CDK5RAP3, CDK5regulatory subunit associated protein 3; ChFP, mCherry fluorescent protein; DDRGK1, DDRGKdomain containing 1; EBV, Epstein-Barr virus; eGFP, enhancedGFP; ER-RQC, endoplasmicreticulum-associated ribosome quality control; LCL, EBV-carryinglymphoblastoid cell line; GFP, green fluorescent protein; RQC, ribosome quality control; SRP, signal recognition particle; UFM1, ubiquitin fold modifier 1; UFL1, UFM1 specific ligase 1.

Cell cycle-dependent gene expression analysis is particularly important as numerous genes show tightly regulated expression patterns at different phases of the cell cycle. For cancer cells, analysis of cell cycle-related events is of paramount significance since tumorigenesis is characteristically coupled to cell cycle perturbations. RT-qPCR is a highly sensitive technique to investigate cell cycle-dependent transcriptional regulation. However, for reliable evaluation of qPCR data reference genes with stable mRNA expression are required. Although several studies investigating cell cycle-dependent gene expression employ frequently used reference genes, the suitability of these reference genes has not been thoroughly investigated so far. Moreover, such potential reference genes for cell cycle analysis have not been described in the literature. Therefore, we aimed to identify reference genes characterized with stable expression throughout the cell cycle in MOLT4 and U937 human leukemia cell lines synchronized with RO-3306 CDK1 inhibitor using RT-qPCR. Here we show that for cell cycle-dependent gene expression analysis the commonly used TBP is suitable, while the recently recognized reference genes SNW1 and CNOT4 are applicable in a cell line-dependent manner. We also suggest that proper selection of reference genes for each experimental condition is crucial for reliable normalization as these aspects can severely compromise conclusions., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Immune cell populations in the intestinal muscularis propria during colitis are poorly resolved. Maintaining homeostasis in this niche is critical, highlighted by the poorer prognosis of inflammatory bowel disease associated with muscularis propria inflammation., Methods: This study utilizes single-cell RNA sequencing to survey the immune cell populations within the muscularis propria of normal colon and dextran sodium sulfate-induced colitis. Findings are validated by immunohistochemistry, flow cytometry and cell-lineage tracing in vivo, and in vitro assays with muscularis macrophages (MMφ)., Results: In naïve conditions, transcriptional duality is observed in MMφs with 2 major subpopulations: conventional resident Cx3cr1+ MMφs and Lyve1+ MMφs. The Lyve1+ population is phagocytic and expresses several known MMφ markers in mouse and human, confirming their identity as a bona fide MMφ subset. Single-cell transcriptomics indicate that resident MMφs are retained during colitis and exhibit plasticity toward an inflammatory profile. Lyve1+ MMφs, which express anti-inflammatory marker CD163, are absent during colitis, as confirmed by flow cytometry. In contrast, lineage tracing finds that resident Cx3cr1+ MMφs remain during colitis and are not completely replaced by the inflammatory infiltrating monocytes. In vitro studies provide biological evidence of the plasticity of resident Cx3cr1+ MMφs in response to lipopolysaccharide (LPS), mirroring transcriptional observations in vivo of their inflammatory plasticity. Potential markers for colitic MMφs, validated in animal models and in individuals with ulcerative colitis, are identified., Conclusions: Our findings contribute to the understanding of the immune system in the muscularis propria niche during colitis by resolving the heterogeneity and origins of colitic MMφs., (© The Author(s) 2024. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Both germline and somatic variants contribute to the genetic background and pathogenesis of melanoma. Germline variants include the presence of rare pathogenic or likely pathogenic variants of high, medium, and low penetrance melanoma-predisposing genes. Rare variants of high penetrance melanoma-predisposing genes are associated with melanoma development, whereas the medium and low penetrance predisposing genes can significantly increase melanoma risk. In this study, we clarified the germline genetic background of a Hungarian melanoma cohort (n = 17). Using a gene panel of 30 melanoma-predisposing genes, germline genetic variants were identified in 10 of the 17 patients (58.82%). A novel, likely pathogenic, missense variant (p.Y143C) in a medium penetrance melanoma-predisposing gene, melanocortin 1 receptor gene (MC1R), and two novel, likely pathogenic nonsense variants in low penetrance genes, p.Q218Ter in caspase 8 (CASP8) and p.Q40Ter in the fat mass- and obesity-associated (FTO) gene were detected. This study highlights the importance of elucidating the germline genetic background of melanoma, which may improve prediction of individual risk and the risk of family members and to optimize preventive, screening, and therapeutic measures for each patient and melanoma-prone families., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)