Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Syntrophin Binds to an Alternatively Spliced Exon of Dystrophin

Andrew H. Ahn and Louis M. Kunkel
The Journal of Cell Biology
Vol. 128, No. 3 (Feb., 1995), pp. 363-371
Stable URL: http://www.jstor.org/stable/1616651
Page Count: 9
  • More info
  • Cite this Item
Syntrophin Binds to an Alternatively Spliced Exon of Dystrophin
Preview not available

Abstract

Dystrophin, the protein product of the Duchenne muscular dystrophy locus, is a protein of the membrane cytoskeleton that associates with a complex of integral and membrane-associated proteins. Of these, the 58-kD intracellular membrane-associated protein, syntrophin, was recently shown to consist of a family of three related but distinct genes. We expressed the cDNA of human β 1-syntrophin and the COOH terminus of human dystrophin in reticulocyte lysates using an in vitro transcription/translation system. Using antibodies to dystrophin we immunoprecipitated these two interacting proteins in a variety of salt and detergent conditions. We demonstrate that the 53 amino acids encoded on exon 74 of dystrophin, an alternatively spliced exon, are necessary and sufficient for interaction with translated β 1-syntrophin in our assay. On the basis of its alternative splicing, dystrophin may thus be present in two functionally distinct populations. In this recombinant expression system, the dystrophin relatives, human dystrophin related protein (DRP or utrophin) and the 87K postsynaptic protein from Torpedo electric organ, also bind to translated β 1-syntrophin. We have found a COOH-terminal 37-kD fragment of β 1-syntrophin sufficient to interact with translated dystrophin and its homologues, suggesting that the dystrophin binding site on β 1-syntrophin occurs on a region that is conserved among the three syntrophin homologues.

Page Thumbnails

  • Thumbnail: Page 
363
    363
  • Thumbnail: Page 
364
    364
  • Thumbnail: Page 
365
    365
  • Thumbnail: Page 
366
    366
  • Thumbnail: Page 
367
    367
  • Thumbnail: Page 
368
    368
  • Thumbnail: Page 
369
    369
  • Thumbnail: Page 
370
    370
  • Thumbnail: Page 
371
    371