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Here, Deol et al. use genetic screens in gene-edited reporter cell lines to identify regulators of ferroptosis suppressor protein 1 (FSP1) expression and stability. They show that vitamin B2 metabolism stabilizes FSP1 through flavin adenine dinucleotide binding, preventing its degradation and ferroptosis sensitization.

CRISPR–Cas9 screening identifies CLCC1 as a factor that increases neutral lipid flux to prevent hepatic steatosis and promotes nuclear pore complex assembly by promoting membrane bending and fusion.

James Olzmann discusses the groundbreaking work of Ron Kopito and colleagues, which demonstrated that a CFTR mutant is ubiquitinated and degraded by the cytosolic 26S proteasome. This discovery contributed to our understanding of ERAD and had important implications for the development of therapeutic agents for cystic fibrosis.

A molecule designed to activate iron locked up in organelles called lysosomes and thereby induce cell death might offer a way to tackle treatment-resistant cancer.

Lange et al. identify a lipid droplet quality control pathway in which FSP1 safeguards stored neutral lipids from lipid peroxidation, thereby preventing the induction of ferroptosis.

FSP1 is a key suppressor of lipid peroxidation and ferroptosis, yet it is largely dispensable in standard cell culture models. Two new studies now show that FSP1 becomes essential for tumour growth in vivo, establishing it as a context-specific cancer vulnerability and highlighting the therapeutic potential of FSP1 inhibition.

LRP8 regulation of cellular selenium promotes ferroptosis resistance in cancer. Low selenium leads to ribosome stalling, ribosome collisions and early GPX4 translation termination.

A synthetic lethal CRISPR–Cas9 screen identifies ferroptosis suppressor protein 1 as a key ferroptosis-resistance factor, the expression of which correlates with ferroptosis resistance in hundreds of cancer cell lines.

Mathiowetz and Olzmann review our current understanding of the mechanisms of lipid droplet biogenesis and turnover, the transfer of lipids and metabolites at membrane contact sites, and the role of lipid droplets in regulating fatty acid flux in lipotoxicity and cell death.

Genetic screens uncover a bioactivation pathway for Lasonolide A involving enrichment in lipid droplets and cleavage into a cytotoxic, soluble metabolite by a lipid droplet-associated serine hydrolase. These findings identify enzymatically regulated phase partitioning as a drug activation mechanism.

Lee, Park et al. show that selenium has the ability to directly regulate the redox state of ubiquinone by donating electrons from hydrogen selenide via sulfide quinone oxidoreductase, thus preventing lipid peroxidation.

The natural product nimbolide covalently reacts with a functional cysteine of the E3 ubiquitin ligase RNF114, resulting in impaired substrate recognition and degradation, enabling the use of nimbolide for targeted protein degradation.

Endoplasmic reticulum–associated degradation (ERAD) is a cellular protein quality-control process that disposes of proteasomal substrates from the early secretory pathway. Recent work shows that the endoplasmic reticulum–resident rhomboid protease RHBDL4 facilitates ERAD by recognizing and cleaving integral membrane substrates. The work indicates that intramembrane proteolysis may have a general role in the extraction of misfolded membrane proteins from the endoplasmic reticulum.

Endoplasmic reticulum-associated degradation (ERAD) substrates must be dislocated across the ER membrane through a process driven by the ATPase p97/VCP, and Derlins are thought to be part of the dislocation machinery. New data identify Derlin-1 as an inactive member of the rhomboid family that facilitates the release of ERAD substrates from the ER, following their transfer across the membrane.

A covalent ligand that targets C277 of ATP6V1A was identified resulting in enhanced v-ATPase activity, inhibition of mTORC1 signaling, increased lysosomal acidification, activation of autophagy and clearance of toxic protein aggregates.

Ferroptosis is a non-apoptotic, iron-dependent cell death mechanism driven by plasma membrane lipid peroxidation and subsequent plasma membrane rupture. Various cellular compartments and organelles contribute to regulating susceptibility to ferroptosis. This regulation involves a plethora of mechanisms centred on iron metabolism and storage, lipid metabolism, and redox balance.

Improperly folded proteins are targeted for destruction through the endoplasmic-reticulum-associated degradation pathway (ERAD). Kopito and colleagues present a high-resolution interaction analysis of the ERAD system in combination with functional genomics, and identify new ERAD components.

Lipid droplets are storage organelles that are important for the regulation of lipid and energy homeostasis, and that serve as buffers against lipotoxicity. Recent studies on the biology of lipid droplets have led to new discoveries about their biogenesis and the complexity of their interactions with other organelles at membrane contact sites.