Calreticulin is essential for integrin-mediated calcium signalling and cell adhesion
M G Coppolino1, M J Woodside, N Demaurex
1Division of Cancer Research, Sunnybrook Health Science Centre, Toronto, Ontario, Canada.
Nature
|April 24, 1997
Summary
Calreticulin is crucial for integrin-mediated cell adhesion and signaling. Calreticulin deficiency impairs cell adhesion and the calcium influx essential for integrin function.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Integrins mediate cell adhesion and signal transduction.
- Calreticulin interacts with integrin alpha-subunits, influencing cell adhesion.
- Understanding calreticulin's role in integrin function is vital.
Purpose of the Study:
- To investigate the role of calreticulin in integrin-mediated cell adhesion and signaling.
- To determine calreticulin's impact on calcium transients initiated by integrin engagement.
Main Methods:
- Development of calreticulin-deficient embryonic stem (ES) cells and fibroblasts.
- Assessment of integrin-mediated adhesion in wild-type and calreticulin-deficient cells.
- Analysis of cytosolic calcium concentration changes upon integrin engagement.
Main Results:
- Calreticulin-deficient cells exhibit severely impaired integrin-mediated adhesion.
- Integrin expression remains unaltered in the absence of calreticulin.
- Calreticulin deficiency abolishes the calcium transient typically induced by integrin engagement, without affecting endomembrane calcium stores.
Conclusions:
- Calreticulin is an essential modulator of integrin adhesive functions.
- Calreticulin plays a critical role in integrin-initiated signaling pathways, particularly calcium influx.
- Calreticulin is not significantly involved in the storage of luminal calcium.
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