Curbing the Killer Instinct

submitted by: JCB
Natural Killer (NK) cells distinguish target cells from surrounding healthy tissue by integrating signals from a variety of activating and inhibitory receptors. Abeyweera et al. reveal that signals from inhibitory receptors limit NK cell activity by remodeling contacts with potential targets and inducing NK cell retraction. This biosights episode presents the paper by Abeyweera et al. from the February 21st, 2011, issue of The Journal of Cell Biology, and includes an interview with senior...

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...

Seeing organelles live in concert

submitted by: JCB
Centrosome positioning is thought to be important for both neuronal migration and axonogenesis. To investigate centrosome dynamics in vivo, Distel et al. develop a new method to simultaneously visualize multiple subcellular compartments in live zebrafish embryos. This biosights episode presents the paper by Distel et al. from the November 15, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Reinhard Köster (Helmholtz Zentrum, Munich, Germany). Produced...

Pulling centrosomes to the forward position

submitted by: JCB
Most migrating cells place their centrosome in front of the nucleus, facing the direction in which the cell is moving. Manneville et al. identify a signaling pathway that moves the centrosome into position by recruiting the motor protein dynein to leading edge microtubules. This biosights episode presents the paper by Manneville et al. from the November 1, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Sandrine Etienne-Manneville (Institut Pasteur,...

Dynein and kinesin generate nuclear power

submitted by: JCB
Many cellular processes, including polarization and differentiation, require the nucleus to move to a specific location within the cytoplasm. Fridolfsson and Starr reveal how the microtubule motors dynein and kinesin-1 control the bi-directional movements of nuclei in the embryonic hypoderm of C. elegans. This biosights episode presents the paper by Fridolfsson and Starr from the October 4, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Daniel Starr...

T Cells Rho across the endothelium

submitted by: JCB
During an immune response, T cells move into tissues from the vasculature by crossing the endothelial cell layer lining blood vessel walls. Heasman et al. reveal that this transendothelial migration requires signaling at both the front and back of leukocytes by the small GTPase RhoA. This biosights episode presents the paper by Heasman et al. from the August 23, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Anne Ridley. Produced by Caitlin Sedwick...

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...

Laminin Adhesions Help Microtubules Reach Base

submitted by: JCB
Microtubules align along the apical-basal axis of epithelial cells with their plus ends pointing to the basal side. Hotta et al. reveal how signals from the extracellular matrix establish this arrangement by recruiting the microtubule-anchoring factors LL5s to the basal cell cortex. This biosights episode presents the paper by Hotta et al. from the May 31, 2010 issue of The Journal of Cell Biology, and includes an interview with senior author Yuko Mimori-Kiyosue. Produced by Caitlin...