CELL SCIENTISTS TO WATCH
CELL SCIENCE AT A GLANCE
Summary: Mammalian septins associate with distinct subsets of actin filaments and microtubules, comprising a unique regulatory module for the spatial patterning and positioning of cytoskeletal networks.
Summary: This Review provides an overview of how the cell regulates its actin monomer pool, focusing on factors that could create distinct groups of G-actin, and proposes an active role for G-actin in cytoskeletal dynamics.
Steric hindrance in the upper 50 kDa domain of the motor Myo2p leads to cytokinesis defects in fission yeast
Summary: An unbiased genetic screen uncovers a mutation that reverses a steric clash in the myosin II motor head, which was previously reported to cause defective actomyosin ring-dependent cytokinesis in fission yeast.
Migration against the direction of flow is LFA-1-dependent in human hematopoietic stem and progenitor cells
Summary: KG1a cells and primary HSPCs migrate against the direction of shear flow on cellular adhesion molecules and endothelial monolayers, and this upstream migration is exclusively dependent upon LFA-1 (αLβ2).
Rap1B promotes VEGF-induced endothelial permeability and is required for dynamic regulation of the endothelial barrier
Summary: Rap1 has been defined as an adhesion-promoting molecule but Rap1B is shown to promote adherens junction disassembly, whereas Rap1A is required for junction maintenance; both isoforms promote junction re-formation following injury.
PAWS1 controls cytoskeletal dynamics and cell migration through association with the SH3 adaptor CD2AP
Summary: PAWS1 (also known as FAM83G) controls cell migration by influencing the organization of F-actin and focal adhesions and the distribution of the actin stress fibre network through its association with CD2AP.
TGF-β induces oncofetal fibronectin that, in turn, modulates TGF-β superfamily signaling in endothelial cells
Summary: TGF-β and oncofetal fibronectin (FN) expression positively correlate in glioblastoma vasculature. In endothelial cells, TGF-β induces oncofetal FN, in turn modulating TGF-β superfamily signaling.
Summary: Under high-temperature stress, the yeast MAP kinase Hog1 is sequestered into stress granules through its N-terminal β-sheet structure, which downregulates Hog1 activity and circumvents cell death.
Summary: Glucose deprivation promotes primary cilium formation through mTORC1 inactivation. The cell cycle inhibitor p27KIP1, which is upregulated upon mTORC1 inactivation, plays a crucial role in rapamycin-induced ciliogenesis.
The methyltransferase SET9 regulates TGFB1 activation of renal fibroblasts via interaction with SMAD3
Summary: SET9 regulates key disease processes under the control of TGFB1 in isolated human kidney fibroblasts, making SET9 an attractive target for treatment of chronic kidney disease.
NudE regulates dynein at kinetochores but is dispensable for other dynein functions in the C. elegans early embryo
Highlighted Article: The sole C. elegans homolog of NudE and NudEL, ubiquitous co-factors of the molecular motor dynein, contributes to chromosome segregation fidelity in early embryogenesis.
Summary: FFA–VAP interactions regulate lipid transfer activity in Drosophila photoreceptors during PLC signalling.
Summary: Leu uptake via the Leu transporter rather than via endocytosis is responsible for mTORC1 activation by amino acids. The dynamin and endocytosis inhibitor dynasore does not affect Leu uptake but abolishes mTORC1 activation.
Highlighted Article: The interruption of the intracellular trafficking of Smo before it undergoes lysosome-mediated degradation leads to a high level of Smo accumulation, which is activated independently of ligand stimulation.
Two spatially distinct kinesin-14 proteins, Pkl1 and Klp2, generate collaborative inward forces against kinesin-5 Cut7 in S. pombe
Summary: Balance of forces generated by kinesin-5 and kinesin-14 is crucial for spindle bipolarity. Two fission yeast kinesin-14 proteins localize to different structures, collaboratively producing inward forces against kinesin-5-mediated outward force.
A self-inhibitory interaction within Nup155 and membrane binding are required for nuclear pore complex formation
Highlighted Article: Membrane binding and an auto-inhibitory self-interaction within Nup155 is crucial for assembly of nuclear pore complexes in the nuclear envelope.
Distinct roles for plasma membrane PtdIns(4)P and PtdIns(4,5)P2 during receptor-mediated endocytosis in yeast
Summary: At the plasma membrane, PtdIns(4)P does not simply serve as an immediate precursor to PtdIns(4,5)P2, but plays a role in recruiting cargo to clathrin-coated pits during receptor-mediated endocytosis.
Highlighted Article: A FRET biosensor reveals DDX3X as an essential activator of the CK1 kinase in living cells. Its CK1-activating function is counteracted by its ATPase activity and also by CK1 peptides.
Highlighted Article: Biomaterials, such as in medical implants, with spiky surfaces induce phagocytic processes. Plasma polymer nanocoating is able to alleviate unfavorable cell physiological reactions on microtopographies.
Summary: Multiple prolines in the helical repeat of karyopherins play essential roles in the structural flexibility of these molecules and their passage through the nuclear pore complex, as well as in proper mitotic progression.
Loss of ADAM9 expression impairs β1 integrin endocytosis, focal adhesion formation and cancer cell migration
Summary: ADAM9 knockdown reduces the internalization of β1 integrin, resulting in the accumulation of β1 integrin at the cell surface, reduced focal adhesion turnover and perturbed cancer cell migration.
TOOLS AND RESOURCES
High-content tripartite split-GFP cell-based assays to screen for modulators of small GTPase activation
Summary: The development of a fluorescent reporter of GTPase activation based on tripartite split-GFP that enables the evaluation of GEF activity and the effect of modulators of GTPase activation in a high-content analysis.