IN THIS ISSUE
CELL SCIENTISTS TO WATCH
CELL SCIENCE AT A GLANCE
Defective signaling, osteoblastogenesis and bone remodeling in a mouse model of connexin 43 C-terminal truncation
Highlighted Article: The C-terminal domain of Cx43 in skeletal tissue affects signaling cascades and osteoblast function. Truncation of this domain recapitulates key aspects of Cx43 conditional deletion in bone.
Rab2a and Rab27a cooperatively regulate the transition from granule maturation to exocytosis through the dual effector Noc2
Summary: Although regulated exocytosis comprises several sequential steps, the mechanisms coordinating each step are poorly understood. These findings suggest that Noc2 regulates the transition between Rab2a- and Rab27a-mediated exocytosis.
Highlighted Article: Disrupting a new HECT ubiquitin ligase restores chemotaxis and development in a Dictyostelium mutant deficient in the Pia subunit of the TORC2 complex (Rictor in mammals), which regulates cAMP relay and cell migration.
Regulation of ciliary retrograde protein trafficking by the Joubert syndrome proteins ARL13B and INPP5E
Summary: Mutations in the genes encoding ARL13B and INPP5E are causative for Joubert syndrome. ARL13B interacts with INPP5E and regulates IFT-A-mediated retrograde protein trafficking within cilia.
Highlighted Article: PDGFRβ is internalized via clathrin-dependent and -independent routes, the latter involving RhoA–ROCK, Cdc42 and galectin-3. Inhibition of any route impairs activation of STAT3 but not other PDGFRβ effectors.
The LINC complex contributes to heterochromatin organisation and transcriptional gene silencing in plants
Summary: The plant LINC complex contributes to heterochromatin position at the nuclear periphery, maintains transcriptional gene silencing and participates in compaction of heterochromatic sequences in cotyledon epidermis and root hair cells.
PIGN prevents protein aggregation in the endoplasmic reticulum independently of its function in the GPI synthesis
Summary: By using visualized secreted proteins markers, we identify that PIGN/PIGN-1 has an unexpected role in protein quality control preventing protein aggregation within the ER.
Δ40p53α suppresses tumor cell proliferation and induces cellular senescence in hepatocellular carcinoma cells
Summary: Δ40p53 exerts tumor suppressor activity that is associated with upregulation of p53-target gene expression and induces senescence in hepatocellular carcinoma cell lines.
ICAP-1 monoubiquitylation coordinates matrix density and rigidity sensing for cell migration through ROCK2–MRCKα balance
Summary: ICAP-1 monoubiquitylation by Smurf1 coordinates fibronectin matrix density and rigidity sensing for cell migration by promoting the switch from a ROCK2- to an MRCKα-mediated contractility pathway.
TOOLS AND TECHNIQUES
Patterns of organelle ontogeny through a cell cycle revealed by whole-cell reconstructions using 3D electron microscopy
Highlighted Article: Serial block face scanning electron microscopy was used to reconstruct whole individual T. brucei cells throughout the cell division cycle to investigate the spatial and temporal changes in organelle dynamics in a quantitative manner.
A high-sensitivity bi-directional reporter to monitor NF-κB activity in cell culture and zebrafish in real time
Summary: We describe a new bi-directional NF-κB reporter that is significantly more sensitive than other available reporters and permits the detection of the endogenous NF-κB activation at high spatiotemporal resolution in vitro and in vivo.