The Editorial Board of Molecular Biology of the Cell has highlighted the following articles from the April 2016 issues. From among the many fine articles in the journal, the Board selects for these Highlights articles that are of broad interest and significantly advance knowledge or provide new concepts or approaches that extend our understanding.
HeLa cancer cells invade a 3D collagen matrix. A spheroid of HeLa cells was embedded in a collagen matrix into which individual cells invaded for 24 hours. In the absence of the tumor suppressor LKB1, cells invade in a predominantly rounded, amoeboid phenotype. Data presented by Konen and Wilkinson et al. (Mol. Biol. Cell 27, 1069–1084) suggest that a combination of kinase-dependent and -independent defects resulting from LKB1 inactivation create a uniquely invasive cell with aberrant polarity and adhesion signaling that drive invasion into the microenvironment. Cells stably express empty GFP (green) and were stained for actin (red) and nucleus (DAPI, blue). (Image: Scott Wilkinson and Adam Marcus, Emory University)
LKB1 kinase-dependent and -independent defects disrupt polarity and adhesion signaling to drive collagen remodeling during invasion
Jessica Konen, Scott Wilkinson, Byoungkoo Lee, Haian Fu, Wei Zhou, Yi Jiang, and Adam I. Marcus
Farnesylation of the LKB1 C-terminal domain promotes mesenchymal polarization and directional persistence during three-dimensional invasion by activating the Rho-GTPase RhoA in a kinase-independent manner. Conversely, LKB1 kinase activity represses FAK activity through MARK1, which subsequently inhibits downstream collagen remodeling during invasion.
Mol. Biol. Cell 27 (7), 1069–1084
An improved smaller biotin ligase for BioID proximity labeling
Dae In Kim, Samuel C. Jensen, Kyle A. Noble, Birendra KC, Kenneth H. Roux, Khatereh Motamedchaboki, and Kyle J. Roux
A smaller promiscuous biotin ligase for proximity biotinylation called BioID2 enables more-selective targeting of fusion proteins, requires less biotin supplementation, exhibits enhanced labeling of proximate proteins, and demonstrates the use of a flexible linker to modulate the biotin-labeling radius.
Mol. Biol. Cell 27 (8), 1188–1196
Unique spatiotemporal activation pattern of Cdc42 by Gef1 and Scd1 promotes different events during cytokinesis
Bin Wei, Brian S. Hercyk, Nicholas Mattson, Ahmad Mohammadi, Julie Rich, Erica DeBruyne, Mikayla M. Clark, and Maitreyi Das
Cdc42 is activated in a unique spatiotemporal manner during cytokinesis due to the localization of its GEFs, Gef1 and Scd1. The fission yeast Gef1 localizes to the actomyosin ring and promotes timely onset of ring constriction. Scd1 localizes to the ingressing membrane to promote septum formation.
Mol. Biol. Cell 27 (8), 1235–1245
