Slipping or gripping? Fluorescent speckle microscopy in fish keratocytes reveals two different mechanisms for generating a retrograde flow of actin.

ABSTRACT: Fish keratocytes can generate rearward directed traction forces within front portions of the lamellipodium, suggesting that a retrograde flow of actin may also occur here but this was not detected by previous photoactivation experiments. To investigate the relationship between retrograde flow and traction force generation, we have transfected keratocytes with GFP-actin and used fluorescent speckle microscopy, to observe speckle flow. We detected a retrograde flow of actin within the leading lamellipodium that is inversely proportional to both protrusion rate and cell speed. To observe the effect of reducing contractility, we treated transfected cells with ML7, a potent inhibitor of myosin II. Surprisingly, ML7 treatment led to an increase in retrograde flow rate, together with a decrease i

SUBMITTER: Jurado C 

PROVIDER: S-EPMC545886 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature