Back to Search
Start Over
Beta 1 integrin-dependent binding of Jurkat cells to fibronectin is regulated by a serine-threonine phosphatase.
- Source :
-
Journal of leukocyte biology [J Leukoc Biol] 1998 Dec; Vol. 64 (6), pp. 753-8. - Publication Year :
- 1998
-
Abstract
- We investigated the effects of signaling molecule inhibitors on the expression and function of beta1 integrins in Jurkat cells. Jurkat cells expressed alpha4beta1 and alpha5beta1, with significant levels of constitutively activated beta1 integrins as assessed by labeling with mAb 15/7 that distinguishes between activation states. Adhesion to fibronectin (Fn) was mediated equally through alpha4 and alpha5 subunits, and was potentiated by the beta1 integrin activating mAb 8A2. Fn adhesion was decreased by okadaic acid through effects on both alpha4beta1, and alpha5beta1. Tyrphostin A23 also decreased adhesion but was less potent. Neither inhibitor had any effect on the surface expression of total or activated beta1 integrins. The effect of tyrphostin was completely reversed by 8A2; the effect of okadaic acid was only partially reversed. Using Calyculin A, we determined that Jurkat adhesion to Fn was regulated via protein phosphatase 1, independent of the levels of integrins or integrin activation epitopes. Activation of Jurkat cells with a CD3-stimulating mAb enhanced adhesion to Fn and was partially blocked by okadaic acid. These data demonstrate different regulatory pathways for constitutive versus activation-dependent adhesion via beta1 integrins, and implicate both tyrosine kinases and serine-threonine phosphatases in integrin function.
- Subjects :
- CD3 Complex physiology
Humans
Integrin beta1 metabolism
Jurkat Cells metabolism
Marine Toxins
Okadaic Acid pharmacology
Oxazoles pharmacology
Protein Phosphatase 1
Signal Transduction drug effects
Signal Transduction physiology
Fibronectins metabolism
Integrin beta1 physiology
Jurkat Cells physiology
Phosphoprotein Phosphatases physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0741-5400
- Volume :
- 64
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Journal of leukocyte biology
- Publication Type :
- Academic Journal
- Accession number :
- 9850157
- Full Text :
- https://doi.org/10.1002/jlb.64.6.753