ISSN:
1524-475X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Directed cell migration plays an important role in wound healing and many other cellular processes. To move directionally, a cell must become asymmetric and establish a dominant protrusion in which localized actin polymerization is a hallmark. We demonstrate that Arp2/3 protein complex, an actin polymerization nucleator consisting of seven protein subunits, is localized to the leading protrusions of cells in culture and in rat healing wounds. The localization of the Arp2/3 protein complex is consistent with its function to promote protrusion and migration. However, the mechanism that restricts the localization of this complex in migrating cells remains unknown. We demonstrate that messenger RNAs (mRNAs) for all the seven subunits of the Arp2/3 complex are localized at the leading protrusions of cells in culture and in wounds. This is the first evidence that mRNAs encoding a protein complex are co-localized to a common site of function. Interestingly, mRNA for Dia-I, a formin protein and another actin nucleator for actin bundles (such as stress fibers), is not localized. Such differential localization of mRNAs for the two actin nucleators suggests that these two functions are sequestered by mRNA sorting. We also demonstrate that the Arp2/3 mRNA localization is dependent on both the actin and microtubule cytoskeletons because disrupting either system abolishes Arp2/3 mRNA localization. The expression and localization of Arp2/3 mRNAs are dependent on serum, indicating Arp2/3 mRNA expression and sorting are consequences of a cellular response to the extracellular environment. Current work focuses on identification of the localization signal sequences and the physiological significance of Arp2/3 mRNA sorting in directed fibroblasts migration.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1067-1927.2004.0abstractcl.x
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