Actin dynamics in mast cells Activation of cell surface receptors is often associated with dramatic changes in actin organisation and cell morphology. Our interest is the molecular mechanism of the signalling to the cytoskeleton and the role of the cytoskeletal rearrangements in effecting cellular functions. We use both intact and permeabilised cells, assessing the effects of manipulation of the cytoskeleton on the secretory responses and vice versa, evaluating the effects induced by various secretagogues on the state of the cytoskeleton.
Confocal microscopy is used to follow the spatial and temporal changes in actin morphology.
This is done in parallel with observations of the secretory granules and actin-regulatory proteins. A longitudinal section through the actin cortex of a resting mast cell attached to a fibronectin-coated glass coverslip. The image demonstrates the prominence of actin filaments at the periphery of a resting cell, while the intracellular space is mostly empty. Upon activation, cell interior becomes filled with actin filaments. A merged image of equatorial slices is shown.