Journal article
A role for the dystrophin-glycoprotein complex as a transmembrane linker between laminin and actin
The Journal of cell biology, Vol.122(4), pp.809-823
08/15/1993
DOI: 10.1083/jcb.122.4.809
PMCID: PMC2119587
PMID: 8349731
Abstract
The dystrophin-glycoprotein complex was tested for interaction with several components of the extracellular matrix as well as actin. The 156-kD dystrophin-associated glycoprotein (156-kD dystroglycan) specifically bound laminin in a calcium-dependent manner and was inhibited by NaCl (IC50 = 250 mM) but was not affected by 1,000-fold (wt/wt) excesses of lactose, IKVAV, or YIGSR peptides. Laminin binding was inhibited by heparin (IC50 = 100 micrograms/ml), suggesting that one of the heparin-binding domains of laminin is involved in binding dystroglycan while negatively charged oligosaccharide moieties on dystroglycan were found to be necessary for its laminin-binding activity. No interaction between any component of the dystrophin-glycoprotein complex and fibronectin, collagen I, collagen IV, entactin, or heparan sulfate proteoglycan was detected by 125I-protein overlay and/or extracellular matrix protein-Sepharose precipitation. In addition, laminin-Sepharose quantitatively precipitated purified dystrophin-glycoprotein complex, demonstrating that the laminin-binding site is accessible when dystroglycan is associated with the complex. Dystroglycan of nonmuscle tissues also bound laminin. However, the other proteins of the striated muscle dystrophin-glycoprotein complex appear to be absent, antigenically dissimilar or less tightly associated with dystroglycan in nonmuscle tissues. Finally, we show that the dystrophin-glycoprotein complex cosediments with F-actin but does not bind calcium or calmodulin. Our results support a role for the striated muscle dystrophin-glycoprotein complex in linking the actin-based cytoskeleton with the extracellular matrix. Furthermore, our results suggest that dystrophin and dystroglycan may play substantially different functional roles in nonmuscle tissues.
Details
- Title: Subtitle
- A role for the dystrophin-glycoprotein complex as a transmembrane linker between laminin and actin
- Creators
- J M Ervasti - Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242K P Campbell - Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242
- Resource Type
- Journal article
- Publication Details
- The Journal of cell biology, Vol.122(4), pp.809-823
- DOI
- 10.1083/jcb.122.4.809
- PMID
- 8349731
- PMCID
- PMC2119587
- ISSN
- 0021-9525
- eISSN
- 1540-8140
- Language
- English
- Date published
- 08/15/1993
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Iowa Neuroscience Institute
- Record Identifier
- 9984068384602771
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