Department of Cell Biology , University of Massachusetts Medical School , Worcester 01655 .
J Cell Biol 126 : 1211-9 ( 1994)
Abstract
Beta-actin mRNA is localized in the leading lamellae of chicken embryo fibroblasts ( CEFs ) ( Lawrence , J. , and R. Singer .
1986 .
Cell .
: 407-415 ) , close to where actin polymerization in the lamellipodia drives cellular motility .
During serum starvation beta-actin mRNA becomes diffuse and non-localized .
Addition of FCS induces a rapid ( within 2-5 min ) redistribution of beta-actin mRNA into the leading lamellae .
A similar redistribution was seen with PDGF , a fibroblast chemotactic factor .
PDGF-induced beta-actin mRNA redistribution was inhibited by the tyrosine kinase inhibitor herbimycin , indicating that this process requires intact tyrosine kinase activity , similar to actin filament polymerization and chemotaxis .
Lysophosphatidic acid , which has been shown to rapidly induce actin stress fiber formation ( Ridley , A. , and A. Hall .
1992 .
Cell .
790:389-399 ) , also increases peripheral beta-actin mRNA localization within minutes .
This suggests that actin polymerization and mRNA localization may be regulated by similar signaling pathways .
Additionally , activators or inhibitors of kinase A or C can also delocalize steady-state beta-actin mRNA in cells grown in serum , and can inhibit the serum induction of peripherally localized beta-actin mRNA in serum-starved CEFs .
These data show that physiologically relevant extracellular factors operating through a signal transduction pathway can regulate spatial sites of actin protein synthesis , which may in turn affect cellular polarity and motility .