Defining of the minimal domain of protein 4.1 involved in spectrin-actin binding.
J Biol Chem
; 270(36): 21243-50, 1995 Sep 08.
Article
en En
| MEDLINE
| ID: mdl-7673158
ABSTRACT
The spectrin-actin-binding domain of protein 4.1 is encoded by a 21-amino acid alternative exon and a 59-amino acid constitutive exon. To characterize the minimal domain active for interactions with spectrin and actin, we functionally characterized recombinant 4.1 peptides containing the 21-amino acid cassette plus varying portions of the 59-amino acid cassette (designated 21.10 to 21.59). Peptide 21.43 was shown fully functional in binary interactions with spectrin (by cosedimentation and coimmunoprecipitation experiments) and in ternary complex formation with spectrin and actin (by an in vitro gelation assay). Further truncation produced peptides incapable of binary interactions but fully competent for ternary complex formation (peptides 21.36 and 21.31), shorter peptides with reduced ternary complex activity and altered kinetics (21.26 and 0.59), and inactive peptides (21.20 and 21.10). Binding studies and circular dichroism experiments suggested that residues 37-43 of the constitutive domain were directly involved in spectrin binding. These data indicate that 4.1-spectrin binary interaction requires the 21-amino acid alternative cassette plus the 43 N-terminal residues of the constitutive domain. Moreover, the existence of two possible ternary complex assembly pathways is suggested one initiated by 4.1-spectrin interactions, and a second by 4.1-actin interactions. The latter may require a putative actin binding motif within the 26 N-terminal residues of the constitutive domain.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neuropéptidos
/
Actinas
/
Espectrina
/
Proteínas del Citoesqueleto
/
Proteínas de la Membrana
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA