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Real-time Live Imaging of T-cell Signaling Complex Formation
Published on: June 23, 2013
Sequential signals toward podosome formation in NIH-src cells
Tsukasa Oikawa1, Toshiki Itoh, Tadaomi Takenawa
1Division of Lipid Biochemistry, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
The Journal of Cell Biology
|July 9, 2008
Summary
Podosome formation is driven by phosphoinositide PtdIns(3,4)P2 accumulation, which recruits Tks5/FISH and N-WASP proteins. This process is crucial for cell adhesion and matrix degradation.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Biology
Background:
- Podosomes are actin-rich adhesion structures involved in matrix degradation.
- Their formation mechanism is poorly understood, particularly the role of phosphoinositides.
Purpose of the Study:
- To elucidate the molecular mechanisms governing podosome formation.
- To investigate the role of phosphoinositides and specific proteins in this process.
Main Methods:
- Expression of phosphoinositide-binding domains.
- Live-cell imaging of Src-transformed NIH3T3 cells.
- Analysis of protein complex formation (Tks5/FISH, Grb2, N-WASP).
Main Results:
- Podosomes in NIH-src cells show enrichment of PtdIns(3,4)P2.
- Src-expression stimulates podosome formation at focal adhesions following PtdIns(3,4)P2 accumulation.
- Tks5/FISH forms an Src-dependent complex with Grb2, and N-WASP binds Tks5/FISH, facilitating podosome assembly.
Conclusions:
- PtdIns(3,4)P2 stabilizes the Tks5/FISH-Grb2 complex at focal adhesions.
- This complex facilitates N-WASP-Arp2/3 signaling, leading to podosome formation.
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