Localization of ribosomes and translation initiation factors to talin/beta3-integrin-enriched adhesion complexes in spreading and migrating mammalian cells.
BACKGROUND
The spatial localization of translation can facilitate the enrichment of proteins at their sites of function while also ensuring that proteins are expressed in the proximity of their cognate binding partners.


RESULTS
Using human embryonic lung fibroblasts and employing confocal imaging and biochemical fractionation techniques, we show that ribosomes, translation initiation factors and specific RNA-binding proteins localize to nascent focal complexes along the distal edge of migrating lamellipodia. 40S ribosomal subunits appear to associate preferentially with beta3 integrin in focal adhesions at the leading edges of spreading cells, with this association strongly augmented by a synergistic effect of cell engagement with a mixture of extracellular matrix proteins. However, both ribosome and initiation factor localizations do not require de novo protein synthesis.


CONCLUSIONS
Taken together, these findings demonstrate that repression, complex post-transcriptional regulation and modulation of mRNA stability could potentially be taking place along the distal edge of migrating lamellipodia.
Willett
Mark
M
Department of Biochemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QG, U.K.
Pollard
Hilary J
HJ
Vlasak
Markete
M
Morley
Simon J
SJ
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D022001:Focal Adhesions / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D039661:Integrin beta3 / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000166:cytology; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism / Q000648:ultrastructure; D020871:RNA Stability; D054682:Ribosome Subunits, Small, Eukaryotic / Q000378:metabolism*; D016608:Talin / Q000235:genetics / Q000378:metabolism*
D016326:Extracellular Matrix Proteins; D039661:Integrin beta3; D010448:Peptide Initiation Factors; D016608:Talin