Protein homeostasis preserves stem cell function, but the underlying mechanisms are largely unknown. A study reveals that protein quality control mediated by the endoplasmic reticulum-associated degradation pathway ensures proper expression of MPL, a key cell surface receptor that promotes haematopoietic stem cell function through niche interaction.

Stem cells need to be protected from genotoxic and proteotoxic stress to maintain a healthy pool throughout life1,2,3. Little is known about the proteostasis mechanism that safeguards stem cells. Here we report endoplasmic reticulum-associated degradation (ERAD) as a protein quality checkpoint that controls the haematopoietic stem cell (HSC)–niche interaction and determines the fate of HSCs. The SEL1L–HRD1

The contribution of ribosome heterogeneity and ribosome-associated proteins to the molecular control of proteomes in health and disease remains unclear. Here, we demonstrate that survival motor neuron (SMN) protein—the loss of which causes the neuromuscular disease spinal muscular atrophy (SMA)—binds to ribosomes and that this interaction is tissue-dependent. SMN-primed ribosomes are preferentially

Programmed death ligand-1 (PD-L1) is well known for its role as an immune checkpoint regulator, but little is known about its function in other cellular processes. A study now shows that in tumour cells PD-L1 mediates pyroptosis, an inflammatory form of cell death, by activating the expression of Gasdermine C, ultimately leading to tumour necrosis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Although pyroptosis is critical for macrophages against pathogen infection, its role and mechanism in cancer cells remains unclear. PD-L1 has been detected in the nucleus, with unknown function. Here we show that PD-L1 switches TNFα-induced apoptosis to pyroptosis in cancer cells, resulting in tumour necrosis. Under hypoxia, p-Stat3 physically interacts with PD-L1 and facilitates its nuclear translocation

Membraneless organelles or condensates form through liquid–liquid phase separation1,2,3,4, which is thought to underlie gene transcription through condensation of the large-scale nucleolus5,6,7 or in smaller assemblies known as transcriptional condensates8,9,10,11. Transcriptional condensates have been hypothesized to phase separate at particular genomic loci and locally promote the biomolecular interactions

Cooperation between DNA, RNA and protein regulates gene expression and controls differentiation through interactions that connect regions of nucleic acids and protein domains and through the assembly of biomolecular condensates. Here, we report that endoderm differentiation is regulated by the interaction between the long non-coding RNA (lncRNA) DIGIT and the bromodomain and extraterminal domain protein

Intestinal stem and progenitor cells replicate and differentiate in distinct compartments, influenced by Wnt, BMP, and other subepithelial cues. The cellular sources of these signals were long obscure because intestinal mesenchyme was insufficiently characterised. In this Review, we discuss how recent mRNA profiles of mouse and human intestinal submucosa, coupled with fine-resolution microscopy and

Transient modulation of the genes involved in immunity, without exerting a permanent change in the DNA code, can be an effective strategy to modulate the course of many inflammatory conditions. CRISPR-Cas9 technology represents a promising platform for achieving this goal. Truncation of guide RNA (gRNA) from the 5′ end enables the application of a nuclease competent Cas9 protein for transcriptional

Ferroptosis is an iron-dependent mode of cell death driven by lipid peroxidation, capable of explosively propagating through a field of cells. Two studies now explore the mechanisms underlying ferroptotic cell death and its spread, as well as its possible in vivo significance, shedding light on some of the burning questions surrounding ferroptosis.

While the formation and concentration of urine are better understood, how kidney epithelial cells generate the energy to drive these functions has remained unclear. A study now reveals that shear stress originating from urinary flow is sensed by the primary cilia of cortical epithelial cells and stimulates lipolysis and oxidative metabolism.

Ferroptosis is a regulated form of necrotic cell death that is caused by the accumulation of oxidized phospholipids, leading to membrane damage and cell lysis1,2. Although other types of necrotic death such as pyroptosis and necroptosis are mediated by active mechanisms of execution3,4,5,6, ferroptosis is thought to result from the accumulation of unrepaired cell damage1. Previous studies have suggested

Organs and cells must adapt to shear stress induced by biological fluids, but how fluid flow contributes to the execution of specific cell programs is poorly understood. Here we show that shear stress favours mitochondrial biogenesis and metabolic reprogramming to ensure energy production and cellular adaptation in kidney epithelial cells. Shear stress stimulates lipophagy, contributing to the production

Rapid wound detection by distant leukocytes is essential for antimicrobial defence and post-infection survival1. The reactive oxygen species hydrogen peroxide and the polyunsaturated fatty acid arachidonic acid are among the earliest known mediators of this process2,3,4. It is unknown whether or how these highly conserved cues collaborate to achieve wound detection over distances of several hundreds

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

PD-L1 has been extensively described as the membrane-bound ligand of PD-1. A recent study discovered a previously unknown role for PD-L1, which is able to bind DNA and thus govern different pathways linked to either evasion of immune surveillance or tumour microenvironment inflammation.

Immunotherapies that target programmed cell death protein 1 (PD-1) and its ligand PD-L1 as well as cytotoxic T-lymphocyte-associated protein 4 (CTLA4) have shown impressive clinical outcomes for multiple tumours. However, only a subset of patients achieves durable responses, suggesting that the mechanisms of the immune checkpoint pathways are not completely understood. Here, we report that PD-L1 translocates

Epigenetic plasticity is a pivotal factor that drives metastasis. Here, we show that the promoter of the gene that encodes the ubiquitin ligase subunit FBXL7 is hypermethylated in advanced prostate and pancreatic cancers, correlating with decreased FBXL7 mRNA and protein levels. Low FBXL7 mRNA levels are predictive of poor survival in patients with pancreatic and prostatic cancers. FBXL7 mediates the

Plasticity of cancer invasion and metastasis depends on the ability of cancer cells to switch between collective and single-cell dissemination, controlled by cadherin-mediated cell–cell junctions. In clinical samples, E-cadherin-expressing and -deficient tumours both invade collectively and metastasize equally, implicating additional mechanisms controlling cell–cell cooperation and individualization

How allelic asymmetry is generated remains a major unsolved problem in epigenetics. Here we model the problem using X-chromosome inactivation by developing “BioRBP”, an enzymatic RNA-proteomic method that enables probing of low-abundance interactions and an allelic RNA-depletion and -tagging system. We identify messenger RNA-decapping enzyme 1A (DCP1A) as a key regulator of Tsix, a noncoding RNA implicated

Autophagy is a catabolic process whereby cytoplasmic components are degraded within lysosomes, allowing cells to maintain energy homeostasis during nutrient depletion. Several studies reported that the CDK inhibitor p27Kip1 promotes starvation-induced autophagy by an unknown mechanism. Here we find that p27 controls autophagy via an mTORC1-dependent mechanism in amino acid-deprived cells. During prolonged

p53 is the most intensively studied tumour suppressor1. The regulation of p53 homeostasis is essential for its tumour-suppressive function2,3. Although p53 is regulated by an array of post-translational modifications, both during normal homeostasis and in stress-induced responses2,3,4, how p53 maintains its homeostasis remains unclear. UFMylation is a recently identified ubiquitin-like modification

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Studies of stem cell behaviour during regeneration have largely focused on understanding how cells make the choice between self-renewal and differentiation. It remains unclear whether cells undergo smooth transitions during differentiation or pause at selective intermediate states. Three studies now explore this question in lung regeneration.

Cellular plasticity allows tumours to adapt to and overcome therapeutic challenges. A recent study uncovered the gene regulatory networks that govern cell states and phenotype switching in melanoma, opening up possibilities to therapeutically target cell states or phenotypic plasticity to render melanoma cells more vulnerable to treatment.

In this issue of Nature Cell Biology, Mercier et al. show that acute changes in membrane tension may be a physiological trigger for ESCRT assembly, which drives membrane scission, luminal vesicle budding, and a wide array of other membrane remodelling events throughout the cell.

The plasma membrane tension strongly affects cell surface processes, such as migration, endocytosis and signalling. However, it is not known whether the membrane tension of organelles regulates their functions, notably intracellular traffic. The endosomal sorting complexes required for transport (ESCRT)-III complex is the major membrane remodelling complex that drives intra-lumenal-vesicle (ILV) formation

Autophagy is a homeostatic process with multiple functions in mammalian cells. Here, we show that mammalian Atg8 proteins (mAtg8s) and the autophagy regulator IRGM control TFEB, a transcriptional activator of the lysosomal system. IRGM directly interacted with TFEB and promoted the nuclear translocation of TFEB. An mAtg8 partner of IRGM, GABARAP, interacted with TFEB. Deletion of all mAtg8s or GABARAPs

Melanoma cells can switch between a melanocytic and a mesenchymal-like state. Scattered evidence indicates that additional intermediate state(s) may exist. Here, to search for such states and decipher their underlying gene regulatory network (GRN), we studied 10 melanoma cultures using single-cell RNA sequencing (RNA-seq) as well as 26 additional cultures using bulk RNA-seq. Although each culture exhibited

There is increasing appreciation that many proteins self-aggregate in cells to form functional subcompartments, some of which exist as a separate liquid phase. A study now identifies the biophysical properties of AKAP95 protein condensates as critical for supporting cancer cell proliferation and RNA splicing.

It remains unknown if biophysical or material properties of biomolecular condensates regulate cancer. Here we show that AKAP95, a nuclear protein that regulates transcription and RNA splicing, plays an important role in tumorigenesis by supporting cancer cell growth and suppressing oncogene-induced senescence. AKAP95 forms phase-separated and liquid-like condensates in vitro and in nucleus. Mutations

Nonstop or stop-loss mutations convert a stop into a sense codon, resulting in translation into the 3′ untranslated region as a nonstop extension mutation to the next in-frame stop codon or as a readthrough mutation into the poly-A tail. Nonstop mutations have been characterized in hereditary diseases, but not in cancer genetics. In a pan-cancer analysis, we curated and analysed 3,412 nonstop mutations

Detection and conversion of mechanical forces into biochemical signals controls cell functions during physiological and pathological processes. Mechanosensing is based on protein deformations and reorganizations, yet the molecular mechanisms are still unclear. Using a cell-stretching device compatible with super-resolution microscopy and single-protein tracking, we explored the nanoscale deformations

Intestinal stem cells (ISCs) are located at the crypt base and fine-tune the balance of their self-renewal and differentiation1,2, but the physiological mechanism involved in regulating that balance remains unknown. Here we describe a transcriptional regulator that preserves the stemness of ISCs by restricting their differentiation into secretory-cell lineages. Interferon regulatory factor 2 (IRF2)

Stem cells undergo dynamic changes in response to injury to regenerate lost cells. However, the identity of transitional states and the mechanisms that drive their trajectories remain understudied. Using lung organoids, multiple in vivo repair models, single-cell transcriptomics and lineage tracing, we find that alveolar type-2 epithelial cells undergoing differentiation into type-1 cells acquire pre-alveolar

Secretory proteins undergo multiple rounds of co- and post-translational quality control checks inside the cell, but how their integrity is maintained outside the cell is an emerging topic. A study establishes a model system to investigate how the extracellular proteome is protected and integrates its findings into existing immune pathways.

The ESCRT-III membrane fission machinery maintains the integrity of the nuclear envelope. Although primary nuclei resealing takes minutes, micronuclear envelope ruptures seem to be irreversible. Instead, micronuclear ruptures result in catastrophic membrane collapse and are associated with chromosome fragmentation and chromothripsis, complex chromosome rearrangements thought to be a major driving force

Lysosomes serve as cellular degradation and signalling centres that coordinate metabolism in response to intracellular cues and extracellular signals. Lysosomal capacity is adapted to cellular needs by transcription factors, such as TFEB and TFE3, which activate the expression of lysosomal and autophagy genes. Nuclear translocation and activation of TFEB are induced by a variety of conditions such

Following fertilization in mammals, the gametes are reprogrammed to create a totipotent zygote, a process that involves de novo establishment of chromatin domains. A major feature occurring during preimplantation development is the dramatic remodelling of constitutive heterochromatin, although the functional relevance of this is unknown. Here, we show that heterochromatin establishment relies on the

Cellular senescence has been widely recognised for decades as a stable arrest of cell proliferation. A recent study identifies senescence establishment and maintenance as a dynamic and reversible process regulated by (in)activation of a predetermined enhancer landscape controlled by the pioneer transcription factor AP-1.

Stem cells tightly link their metabolism to cell fate decisions; however, how cancers co-opt and bypass metabolic pathways for growth advantage remains unclear. New evidence in this issue highlights how cancer stem cells avoid epigenetically driven differentiation by shutting down endogenous serine synthesis and becoming serine auxotrophs.

Cell shape is controlled by the submembranous cortex, an actomyosin network mainly generated by two actin nucleators: the Arp2/3 complex and the formin mDia1. Changes in relative nucleator activity may alter cortical organization, mechanics and cell shape. Here we investigate how nucleation-promoting factors mediate interactions between nucleators. In vitro, the nucleation-promoting factor SPIN90 promotes

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Coat proteins have a central role in vesicular transport by binding to cargoes for their sorting into intracellular pathways. Cargo recognition is mediated by components of the coat complex known as adaptor proteins1,2,3. We previously showed that Arf-GAP with coil-coil, ANK repeat and PH domain-containing protein 1 (ACAP1) functions as an adaptor for a clathrin coat complex that has a function in

Mutations in chromatin-modifying complexes and metabolic enzymes commonly underlie complex human developmental syndromes affecting multiple organs. A major challenge is to determine how disease-causing genetic lesions cause deregulation of homeostasis in unique cell types. Here we show that neural-specific depletion of three members of the non-specific lethal (NSL) chromatin complex—Mof, Kansl2 or

Tumour heterogeneity encompasses both the malignant cells and their microenvironment. While heterogeneity between individual patients is known to affect the efficacy of cancer therapy, most personalized treatment approaches do not account for intratumour heterogeneity. We addressed this issue by studying the heterogeneity of nodal B-cell lymphomas by single-cell RNA-sequencing and transcriptome-informed

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Senescent cells affect many physiological and pathophysiological processes. While select genetic and epigenetic elements for senescence induction have been identified, the dynamics, epigenetic mechanisms and regulatory networks defining senescence competence, induction and maintenance remain poorly understood, precluding the deliberate therapeutic targeting of senescence for health benefits. Here,

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cancer-associated fibroblasts (CAFs) perform diverse roles and can modulate therapy responses1. The inflammatory environment within tumours also influences responses to many therapies, including the efficacy of oncolytic viruses2; however, the role of CAFs in this context remains unclear. Furthermore, little is known about the cell signalling triggered by heterotypic cancer cell–fibroblast contacts

Tissue remodelling during Drosophila embryogenesis is notably driven by epithelial cell contractility. This behaviour arises from the Rho1–Rok-induced pulsatile accumulation of non-muscle myosin II pulling on actin filaments of the medioapical cortex. While recent studies have highlighted the mechanisms governing the emergence of Rho1–Rok–myosin II pulsatility, little is known about how F-actin organization

Osteosarcoma is a type of aggressive malignant bone tumour that frequently metastasizes to lungs, resulting in poor prognosis. However, the molecular mechanisms of lung metastasis of osteosarcoma remain poorly understood. Here we identify exon–intron fusion genes in osteosarcoma cell lines and tissues. These fusion genes are derived from chromosomal translocations that juxtapose the coding region for

It is well accepted that cancers co-opt the microenvironment for their growth. However, the molecular mechanisms that underlie cancer–microenvironment interactions are still poorly defined. Here, we show that Rho-associated kinase (ROCK) in the mammary tumour epithelium selectively actuates protein-kinase-R-like endoplasmic reticulum kinase (PERK), causing the recruitment and persistent education of

Tissue stem cells are the cell of origin for many malignancies. Metabolites regulate the balance between self-renewal and differentiation, but whether endogenous metabolic pathways or nutrient availability predispose stem cells towards transformation remains unknown. Here, we address this question in epidermal stem cells (EpdSCs), which are a cell of origin for squamous cell carcinoma. We find that

The dynamin GTPase is known to bundle actin filaments, but the underlying molecular mechanism and physiological relevance remain unclear. Our genetic analyses revealed a function of dynamin in propelling invasive membrane protrusions during myoblast fusion in vivo. Using biochemistry, total internal reflection fluorescence microscopy, electron microscopy and cryo-electron tomography, we show that dynamin

Acquired therapy resistance is a major problem for anticancer treatment, yet the underlying molecular mechanisms remain unclear. Using an established breast cancer cellular model, we show that endocrine resistance is associated with enhanced phenotypic plasticity, indicated by a general downregulation of luminal/epithelial differentiation markers and upregulation of basal/mesenchymal invasive markers

The transcription factor oestrogen receptor alpha (ERα) has long been targeted for therapeutic benefit in cancer, but drug resistance can emerge through a multitude of mechanisms. A study now reveals how the ERα cistrome can become reprogrammed to confer resistance to tamoxifen in breast cancer.