WHAMM is an Arp2/3 complex activator that binds microtubules and functions in ER to Golgi transport.
Campellone KG, Webb NJ, Znameroski EA, Welch MD.
Cell 134: 148 (2008)

Video 1: Dynamics of GFP-WHAMM-associated membranes in a Cos7 cell over a 10 min timecourse.

Video 2: Dynamics of GFP-WHAMM-associated membranes in a Cos7 cell over a 6 min timecourse.

Video 3: Dynamics of GFP-WHAMM-associated membranes in an NIH 3T3 cell in the presence of nocodazole. The drug was added 3 min into a 9 min time series.

Video 4: Dynamics of GFP-WHAMM-associated membranes in an NIH 3T3 cell in the presence of cytochalasin D. The drug was added 3 min into a 9 min time series.

Video 5: Dynamics of GFP-WHAMM-associated membranes in an NIH 3T3 cell in the presence of latrunculin A. The drug was added 3 min into a 9 min time series.

Video 6: Dynamics of GFP-WAMM(W807A)-associated tubules in an NIH 3T3 cell over a 6 min timecourse.

Dynamic nuclear actin assembly by Arp2/3 complex and a baculovirus WASP-like protein.
Goley ED, Ohkawa T, Mancuso J, Woodruff JB, D'Alessio JA, Cande WZ, Volkman LE, Welch MD
Science 314,464-467 (2006)

Video 1: Actin localization and polymerization in infected TN-368 cells expressing EGFP-actin, viewed from 14:30 to 21:42 hours post infection (hpi). Latrunculin A is added at approximately 20 hpi, causing depolymerization of the discrete nuclear F-actin structures.

Video 2: Actin localization and polymerization in infected TN-368 cells expressing EGFP-actin, viewed from 18:45 to 22:05 hours post infection.

Video 3: Actin localization and polymerization in infected TN-368 cells expressing mCherry-actin, viewed from 5:44 to 22:40 hours post infection.

Video 4: Fluorescence recovery after photobleaching a region of the nucleus in an infected TN-368 cell expressing EGFP-actin. The circle marks the photobleached region.

Video 5: Fluorescence loss in photobleaching of nuclear GFP-actin in a representative infected TN-368 cell that has been treated with latrunculin A.

Plasma membrane organization is essential for balancing competing pseudopod- and uropod-promoting signals during neutrophil polarization and migration.
Bodin S, Welch MD.
Mol Biol Cell 16, 5773-83 (2005)

Video 1: Inhibition of the fMLP-induced chemotaxis response in cholesterol-depleted cells. Control cell (left) or MßCD- treated cell (right) were visualized using DIC microscopy.

Video 2: Cholesterol-depletion increases the chemoattractant sensitivity of the rear edge. Cell was visualized using DIC microscopy.

Video 3: Cholesterol depletion does not inhibit the fMLP-induced formation of a retracting uropod in pertussis toxin- treated cells. Pertussis-toxin (PTX) treated cell (left) and a cell treated with both PTX and MßCD (right), visualized using DIC microscopy.

Video4, Video 5, Video 6: Cholesterol is required to restrict D3-PI synthesis to the pseudopod. Control cell (Video 4) and cholesterol-depleted cells (Videos 5 and 6) expressing PH-Akt-GFP, left panels DIC microscopy, right panels PH- Akt-GFP fluorescence.

Video 7: Distribution of D3-PIs in a control cell during an abrupt reversion of the fMLP gradient visualized by PH-Akt- GFP fluorescence.

Video 8: Distribution of D3-PIs in a cholesterol- depleted cell during an abrupt reversion of the fMLP-gradient visualized by PH-Akt-GFP fluorescence.

Video 9: Cholesterol depletion induces pseudopod formation in a PI3-K- and Gi- dependent manner. Cells expressing PH- Akt-GFP were exposed to a gradient of MbCD diffusing from a micropipette. Cells respond by emitting a pseudopod facing the pipette tip (top panel), accompanied by a modest membrane relocation of PH-Akt-GFP (indicated by white arrow on frame 100 s). This response is prevented in cells pre-treated by pertussis-toxin (middle panel), or wortmannin (lower panel).

A Rickettsia WASP-like protein activates the Arp2/3 complex and mediates actin-based motility.
Robert L. Jeng, Erin D. Goley, Joseph A. D'Alessio, Oleg Y. Chaga, Tatyana M. Svitkina, Gary G. Borisy, Robert A. Heinzen and Matthew D. Welch. Cell Microbiol. 6, 761-769 (2004)

Video 1 Movie of actin structures assembled by RickA-coated beads in Xenopus egg extract that was supplemented with rhodamine-labelled actin and visualized by fluorescence microscopy.