IN THIS ISSUE
CELL SCIENTISTS TO WATCH
An emerging case for membrane pore formation as a common mechanism for the unconventional secretion of FGF2 and IL-1β
Summary: This Opinion article summarises the latest research into the unconventional pathways of secretion for IL-1β and FGF2.
Summary: We review the role of ECM molecules in the formation and function of the notochord, an essential structure in all vertebrates, as well as in the pathogenesis of notochord-related diseases.
Mosaic loss of non-muscle myosin IIA and IIB is sufficient to induce mammary epithelial proliferation
Summary: Deletion of both non-muscle myosin IIA and IIB in a mosaic subset of cells in the mammary epithelium induces tissue growth and proliferation in 3D culture and in vivo.
Highlighted Article: To respond to folding stress in the ER, cells activate the conserved sensor Ire1. We show that iron is required for optimal Ire1 activation and suggest this is because iron is required for ergosterol biosynthesis.
A genome-wide CRISPR screen reconciles the role of N-linked glycosylation in galectin-3 transport to the cell surface
Summary: A CRISPR screen identified genes that regulate the cell surface localization of galectins, and data support a secretion pathway for galectin-3 that is independent of N-linked glycoproteins and extracellular vesicles.
Sub-mitochondrial localization of the genetic-tagged mitochondrial intermembrane space-bridging components Mic19, Mic60 and Sam50
Highlighted Article: By using the novel genetic labels miniSOG and APEX2 combined with electron tomography, the sub-compartmental locations of Mic19, Mic60 and Sam50 were deciphered, which helps determine their physiological function and interaction partners.
Summary: Different sheddases specifically and dynamically distinguish between multiple substrates expressed on the same cell, in a process regulated by Ca2+ coordination of the Shh substrate.
Highlighted Article: SerpinB2, a known inhibitor of urokinase plasminogen activator and tissue plasminogen activator, is a downstream target of p53 and has a role in senescence by stabilizing p21 levels.
Summary: The RET receptor isoforms RET9 and RET51 recruit distinct E3 ubiquitin ligases through assembly of isoform-specific adaptor protein complexes that promote receptor ubiquitylation and internalization.
Highlighted Article: DCAF2 is a maternal factor that is crucial for prevention of DNA re-replication in the first and unique mitotic cell cycle of the zygote in mice, safeguarding zygotic genome stability.
Summary: Connexin 37 may serve as a molecular switch that contributes to cell fate decisions, between cell cycle arrest, cell cycle progression and cell death, in a phosphorylation- and channel-dependent manner.
Conserved cytoplasmic domains promote Hrd1 ubiquitin ligase complex formation for ER-associated degradation (ERAD)
Highlighted Article: A cytoplasmic domain within the ubiquitin ligase Hrd1 recruits cofactors necessary for ligase oligomerisation and activity, which are important for ER-associated degradation (ERAD).
Summary: The deubiquitylating enzyme Ubp12 targets the ubiquitin shuttle factor Rad23 and stabilizes proteasome substrates that are delivered by Rad23, uncovering a novel link between ubiquitin and proteasomal degradation.
Nup153 and Nup50 promote recruitment of 53BP1 to DNA repair foci by antagonizing BRCA1-dependent events
Summary: This study places Nup153 and Nup50 in a molecular pathway that regulates the mutual antagonism between 53BP1 and BRCA1 by promoting intranuclear targeting of 53BP1 to sites of DNA damage.
Summary: Cilia have important roles in cell and developmental biology but little is known about what prevents cilia being made at the wrong time. We show that BCAP is an important inhibitor of ciliogenesis.
Summary: The armadillo protein p0071 controls directional vesicular transport mediated by the KIF3 (kinesin-2) complex, and secretion of respective cancer-relevant cargos from neuroendocrine and pancreatic tumor cells.
Summary: The trafficking of proteasomes, but not synaptic proteins, in Drosophila motor neurons requires the cut up gene revealing a role in cargo specificity for the LC8 family of dynein light chains.
Summary: The CCR2 3′UTR acts as a metastasis suppressor by acting as a competing endogenous RNA for STARD13 and thus inhibiting activation of the RhoA–ROCK1–MLC–F-actin pathway in breast cancer cells.