Journal article
Microinjection of Protein Tyrosine Phosphatases into Fibroblasts Disrupts Focal Adhesions and Stress Fibers
Cell communication & adhesion, Vol.5(3), pp.207-219
1998
DOI: 10.3109/15419069809040292
PMID: 9686318
Abstract
Microinjection and scrape-loading have been used to load cells in culture with soluble protein tyrosine phosphatases (FTPs). The introduction of protein tyrosine phosphatases into cells caused a rapid (within 5 minutes) decrease in tyrosine phosphorylation of major tyrosine phosphorylated substrates, including the focal adhesion kinase and paxillin. This decrease was detected both by blotting whole cell lysates with anti-phosphotyrosine antibodies and visualizing the phosphotyrosine in focal adhesions by immunofluorescence microscopy. After 30 minutes, many of the cells injected with tyrosine phosphatases revealed disruption of focal adhesions and stress fibers. To determine whether this disruption was due to the dephosphorylation of FAK and its substrates in focal adhesions, we have compared the effects of protein tyrosine phosphatase microinjection with the effects of displacing FAK from focal adhesions by microinjection of a dominant negative FAK construct. Although both procedures resulted in a marked decrease in the level of phosphotyrosine in focal adhesions, disruption of focal adhesions and stress fibers only occurred in cells loaded with exogenous protein tyrosine phosphatases. These results lead us to conclude that although tyrosine phosphorylation regulates focal adhesion and stress fiber stability, this does not involve FAK nor does it appear to involve tyrosine-phosphorylated proteins within focal adhesions. The critical tyrosine phosphorylation event is upstream of focal adhesions, a likely target being in the Rho pathway that regulates the formation of stress fibers and focal adhesions.
Details
- Title: Subtitle
- Microinjection of Protein Tyrosine Phosphatases into Fibroblasts Disrupts Focal Adhesions and Stress Fibers
- Creators
- Galen B Schneider - 1Department of Prosthodontics, School of Dentistry Brauer Hall, Chapel Hill, North Carolina, 27599Andrew P Gilmore - 1Department of Prosthodontics, School of Dentistry Brauer Hall, Chapel Hill, North Carolina, 27599Lewis H Romer - 2Cell Biology and Anatomy, University of North Carolina, Chapel Hill, North Carolina, 27599Keith Burridge - 2Cell Biology and Anatomy, University of North Carolina, Chapel Hill, North Carolina, 27599
- Resource Type
- Journal article
- Publication Details
- Cell communication & adhesion, Vol.5(3), pp.207-219
- Publisher
- Informa UK Ltd
- DOI
- 10.3109/15419069809040292
- PMID
- 9686318
- ISSN
- 1541-9061
- eISSN
- 1543-5180
- Language
- English
- Date published
- 1998
- Academic Unit
- Dentistry Administration; Prosthodontics
- Record Identifier
- 9984066083002771
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