Renne et al. show that Seipin promotes the formation of lipid droplets containing either triacylglycerol or steryl esters. It is proposed that interactions between hydroxyl-residues within the Seipin complex and neutral lipid carboxyl esters provide a general mechanism for Seipin-mediated LD formation.

Jiang et al. uncover that ubiquitylated RAP80 and BRCC36 are substrates of deubiquitylation within the BRCA1-A complex. Deubiquitylation prevents auto-inhibition of the complex, allowing RAP80 to bind ubiquitin at DNA damage sites. Autologous deubiquitylation explains the matching ubiquitin-binding and hydrolysis activities within the BRCA1-A complex.

Efficient and effective quantification protocol of membrane contact sites is an urgent demand in precise surveillance of various cellular processes. Liu et al. developed a deep learning–based high-throughput tool for profiling the contact with EM images.

Hannaford et al., identify that the interaction between Kinesin-1 and Pericentrin is essential for the direct transport of centrioles on the interphase microtubule network. This transport is important for the correct segregation of centrioles during asymmetric cell division.

Kucharski et al. show that small changes to phosphorylation of Hec1 and partial phospho-occupancy are sufficient to support mitotic fidelity. They also show that Cdk1–Cyclin B1 localizes to improperly attached kinetochores during mitosis and directly participates in kinetochore–microtubule attachment error correction by phosphorylating Hec1.

Simoes et al. demonstrate that the SLAYGLR/osteopontin motif induces the production of IFN-β in murine pDCs through α4-integrin receptor in the absence of Toll-like receptor activation. This axis not only enhances pDCs’ suppressive function against melanoma tumor growth, but also boosts pDC generation from bone marrow progenitors.

Droubi et al. identify a role for the inositol 5-phosphatase INPP5B in clustering and signaling of the B cell receptor. These effects are mediated by INPP5B-dependent hydrolysis of PI(4,5)P₂ to control cortical actin and B cell receptor dynamics.