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ESCRT-III, a protein complex best known for membrane constriction and sealing during various cellular processes, mediates reassembly of the nuclear envelope during late anaphase.

Repeated contacts between the endoplasmic reticulum (ER) and a subset of endosomes called late endosomes (LEs) is shown to promote microtubule-dependent translocation of LEs to the cell periphery and their subsequent fusion with the plasma membrane to induce outgrowth of neuronal protrusions.

In the presence of incorrectly segregated chromosomes, the Aurora-B-dependent abscission checkpoint prevents the final stage of cytokinesis. Stenmark and colleagues identify a role for the previously uncharacterized protein ANCHR at the checkpoint, where it acts in an Aurora-B-dependent manner to retain the ATPase VPS4 at the midbody.

The endoplasmic reticulum protein DFCP1 is found on omegasomes implicated in autophagosome biogenesis, but its function has remained unknown. Here, Nähse et al. show that DFCP1 is an ATPase that mediates selective autophagy by promoting constriction of large omegasomes.

New inducers of autophagy—the process by which cells use lysosomes to degrade portions of their cytoplasm—are lead compounds for new drugs targeting neurodegenerative protein aggregation diseases.

Autophagy decreases with age, and this is in part attributed to increasing levels of the autophagy-suppressing protein Rubicon. Cell biologists now find another ageing-associated function for Rubicon — the release of exosomes containing microRNAs that control senescence and longevity.

The p62 protein recognizes toxic cellular waste, which is then scavenged by a sequestration process known as self-eating or autophagy. Lack of autophagy leads to accumulation of p62, which is not good for liver cells, as it induces a cellular stress response that leads to disease.

Macropinocytosis permits the cellular uptake of fluids and nutrients via macropinosomes. Here, the authors show that Phafin2 is required for the formation of macropinosomes and permits their transit through dense actin networks.

Vietri et al. show that the micronucleus fails to restrain ESCRT-III spreading due to its small size, resulting in aberrant accumulation of ESCRT-III to drive micronuclear collapse and DNA fragmentation.

WDFY2 is known as a tumour suppressor but its function is unclear. Here, the authors show that WDFY2 interacts with the v-SNARE VAMP3, leading to a suppression of the metalloprotease MT1-MMP secretion, suggesting that WDFY2 acts a tumour suppressor by suppressing MT1-MMP secretion.

The matrix metalloprotease MT1-MMP drives cancer metastasis. Here, the authors demonstrate how invasive cancer cells instigate non-invasive neighbouring cells to become degradative and invasive by transferring catalytically active MT1-MMP fragments.

A new link is reported between regulators of endosomal trafficking and cytokinesis. Production of the phosphoinositide lipid PI3P at the midbody triggers the KIF13A-mediated recruitment of the centrosomal proteins FYVE-CENT and TTC19 to the division site. TTC19 may in turn regulate abscission by control of the ESCRTIII complex.

O’Farrell et al. show that class III PI3K regulates epithelial integrity through endosomal LKB1. Class III PI3K inactivation dysregulates LKB1 to alter cell polarity, and the PtdIns3P effector WDFY2 regulates LKB1.

Lysosomes degrade cellular components, and their membrane is an important signalling hub. Recent insights into the mechanisms that maintain lysosomal membrane homeostasis — including the interplay between membrane damage, repair, lysophagy and lysosome biogenesis — highlight their importance in physiology, in disease and during ageing.

Natural killer (NK) cells are functionally calibrated against self MHC during a process termed education. Here the authors show that NK cell education is associated with the accumulation of dense-core secretory lysosomes for expedited release of granzyme B and Ca²⁺ flux upon target recognition and NK cell activation.

Rab GTPases control intracellular vesicle traffic by acting as regulatable switches that recruit effector molecules when in their GTP-bound form. The functional coupling between multiple Rab GTPases ensures the spatiotemporally coordinated regulation of vesicle traffic.

Which end of a fly embryo becomes the head is partly dictated by the accumulation of bicoid RNA at the anterior pole. The protein that amasses the RNA turns out to be an old acquaintance from a different context.

Phosphoinositides recruit proteins to distinct intracellular membranes. Now, the Phox homology (PX) domain, an evolutionarily conserved protein domain whose function has so far been elusive, has been demonstrated to bind phosphoinositides. The interactions of PX-domain-containing proteins with specific phosphoinositides are critical for cellular activities such as microbial killing and membrane trafficking.

This Review examines recently gained insights into the roles of ESCRT complexes in viral infection, immunity, cancer and neurological disease.

A theoretical model, in vitro reconstitution and in vivo experimentation show that competition between droplet surface tension and membrane sheet instability dictates the form and function of autophagosomal membranes.

Inflammasome activation is a response to bacterial infection but can cause damage and spread infection. Here, the authors use live single-cell imaging to show two mechanisms by which M. tuberculosis causes damage to human macrophage cell plasma membranes, resulting in activation of the NLRP3 inflammasome, pyroptosis and release of infectious particles.

STING ER exit is the rate-limiting step in STING signaling, but the mechanism that drives this process is not understood. Paludan and colleagues identify CxORF56, called STEEP here, as a positive regulator of STING signaling.

Ubiquitin receptors that bind ubiquitinated proteins through ubiquitin-binding domains have key roles in various cellular processes. These receptors are often themselves monoubiquitinated, referred to as coupled monoubiquitination. Now, coupled monoubiquitination has been shown to involve monoubiquitination of a ubiquitin ligase and its subsequent interaction with a ubiquitin receptor.

Intraluminal vesicles are formed by the endosomal sorting complex required for transport (ESCRT) machinery. Here, the authors unravel the timing of vesicle budding, and that endosomal clathrin regulates concerted recruitment of ESCRT subcomplexes, required for efficient membrane remodeling.

During early-stage tumour growth in Drosphila, tumour cells acquire necessary nutrients by triggering autophagy in surrounding cells in the tumour microenvironment.

Given the recent growing interest in interorganelle membrane contact sites, the field will benefit from clear rules to define and study them. In this Perspective, a panel of experts aims to provide this growing field with guidelines for experimental definition and analysis.

Endosomal sorting complexes required for transport (ESCRTs) are key membrane remodellers, which drive the budding, scission and sealing of various cellular membranes. Accordingly, ongoing research focuses on how ESCRTs mediate a wide-range of cellular processes, including cytokinesis, endosome maturation, autophagy, membrane repair and viral replication.