Adducin: a physical model with implications for function in assembly of spectrin-actin complexes.


Journal Article

Adducin binds to spectrin-actin complexes, promotes association of spectrin with actin, and is subject to regulation by calmodulin as well as protein kinases A and C. Adducin is a heteromer comprised of homologous alpha and beta-subunits with an NH2-terminal protease-resistant head domain, connected by a neck region to a COOH-terminal hydrophilic, protease-sensitive region. This study provides evidence that adducin in solution is a mixture of heterodimers and tetramers. CD spectroscopy of COOH-terminal domains of alpha- and beta-adducin bacterial recombinants provides direct evidence for an unstructured random coil configuration. Cross-linking, proteolysis, and blot-binding experiments suggest a model for the adducin tetramer in which four head domains contact one another to form a globular core with extended interacting alpha- and beta-adducin tails. The site for binding to spectrin-actin complexes on adducin was identified as the COOH-terminal tail of both the alpha- and beta-adducin subunits. The capacity of native adducin to recruit spectrin to actin filaments is similar to that of adducin tail domains. Thus, adducin tail domains alone are sufficient to interact with F-actin and a single spectrin and to recruit additional spectrin molecules to the ternary complex.

Full Text

Duke Authors

Cited Authors

  • Hughes, CA; Bennett, V

Published Date

  • August 11, 1995

Published In

Volume / Issue

  • 270 / 32

Start / End Page

  • 18990 - 18996

PubMed ID

  • 7642559

Pubmed Central ID

  • 7642559

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.270.32.18990


  • eng

Conference Location

  • United States