Ouch! Single Cell Wound Repair in Drosophila Embryos

submitted by: JCB
Individual cells must quickly repair any disruptions to their plasma membrane. Abreu-Blanco et al. describe how early Drosophila embryos remodel their membranes and cytoskeleton to seal cell surface wounds. This biosights episode presents the paper by Abreu-Blanco et al. from the May 2, 2011 issue of The Journal of Cell Biology, and includes an interview with senior author Susan Parkhurst (Fred Hutchinson Cancer Research Center, Seattle, WA). Produced by Caitlin Sedwick and Ben Short....

Microtubules Keep Tumor Cells Breathing Easy

submitted by: JCB
The transcription factor HIF-1α is essential for a cell's response to low oxygen conditions. Carbonaro et al. demonstrate that production of HIF-1α protein is regulated by dynamic microtubules and that microtubule-targeting drugs shift HIF-1α mRNA into cytoplasmic P-bodies, where its translation is repressed by miRNAs. This biosights episode presents the paper by Carbonaro et al. from the January 10, 2011, issue of The Journal of Cell Biology, and includes an interview with authors Marisa...

The Spindle's Model Behavior

submitted by: JCB
Dynamic microtubules assemble into a steady state bipolar spindle structure but precisely how this is achieved is unclear. Loughlin et al. develop a computational model that predicts how a few key activities organize microtubules in Xenopus meiotic spindles. This biosights episode presents the paper by Loughlin et al. from the December 27, 2010 issue of The Journal of Cell Biology, and includes an interview with author François Nédélec (EMBL, Heidelberg, Germany). Produced by Caitlin...

Acetylated microtubules let the ER slide

submitted by: JCB
The endoplasmic reticulum is highly dynamic, although little is known about why and how its membrane tubules move. Friedman et al. reveal that ER membranes slide along stable, acetylated microtubules, which might help them contact other organelles such as mitochondria. This biosights episode presents the paper by Friedman et al. from the August 9, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Gia Voeltz. Produced by Caitlin Sedwick and Ben Short....

Long Asters Rock The Spindle

submitted by: JCB
Astral microtubules help position the cytokinetic furrow by confining actomyosin contractility to the cell equator. Rankin and Wordeman reveal that if astral microtubules grow too long, they expand membrane blebs at the mitotic cell poles that squeeze the mitotic spindle back and forth between the two daughter cells. This biosights episode presents the paper by Rankin and Wordeman from the July 12, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Linda...

A Turning Point for Macrophages

submitted by: JCB
Drosophila macrophages disperse themselves around the body during embryogenesis, ready to mount an immune response at the site of a wound. Stramer et al. image the cells in vivo, revealing that they form microtubule "arms" to point them in the right direction and push themselves away from their fellow leukocytes. This biosights episode presents the paper by Stramer et al. from the May 17th, 2010 issue of The Journal of Cell Biology, and includes an interview with lead author Brian Stramer....

Probing the spindle matrix

submitted by: JCB
A microtubule-independent network of proteins called the spindle matrix is involved in assembling mitotic and meiotic spindles, but whether the matrix makes a mechanical contribution to spindle shape is unclear. Gatlin et al. manipulate spindles with microneedles to directly probe the mechanical properties of the spindle matrix. This biosights episode presents the paper by Gatlin et al. from the February 22, 2010 issue of The Journal of Cell Biology, and includes an interview with lead...

Motor-dependent microtubule disassembly driven by tubulin tyrosination

submitted by: JCB
In cells, stable microtubules (MTs) are covalently modified by a carboxypeptidase, which removes the C-terminal Tyr residue of alpha-tubulin. The significance of this selective detyrosination of MTs is not understood. In this study, we report that tubulin detyrosination in fibroblasts inhibits MT disassembly. This inhibition is relieved by overexpression of the depolymerizing motor mitotic centromere-associated kinesin (MCAK). Conversely, suppression of MCAK expression prevents disassembly...
Authors: Leticia Peris

One-Dimensional Topography Underlies Three-Dimensional Fibrillar Cell Migration

submitted by: JCB
Current concepts of cell migration were established in regular two-dimensional (2D) cell culture, but the roles of topography are poorly understood for cells migrating in an oriented 3D fibrillar extracellular matrix (ECM). We use a novel micropatterning technique termed microphotopatterning (µPP) to identify functions for 1D fibrillar patterns in 3D cell migration. In striking contrast to 2D, cell migration in both 1D and 3D is rapid, uniaxial, independent of ECM ligand density, and...
Authors: Andrew Doyle, Francis Wang, Kazue Matsumoto