Protein 4.1 deficiency associated with an altered binding to the spectrin-actin complex of the red cell membrane skeleton.
J Clin Invest
; 94(4): 1651-6, 1994 Oct.
Article
em En
| MEDLINE
| ID: mdl-7929842
ABSTRACT
Protein 4.1 has been defined as a major component of the subcortical skeleton of erythrocytes. It binds the spectrin--actin scaffold through a 10-kD internal domain. This binding requires an essential 21-amino acid sequence motif, Motif I, which is retained by alternative splicing at the late stage of erythroid differentiation. We here analyze the molecular basis of heterozygous 4.1(-) hereditary elliptocytosis, associated with protein 4.1 partial deficiency, in nine related French families. cDNA sequencing revealed a single codon deletion (AAA) resulting in a lysine residue deletion within the 10-kD binding domain, 3' of Motif I. The mutated allele was designated allele 4.1 Aravis. In order to assess the functional effect of the codon deletion, recombinant 10-kD constructs were made and various binding assays were performed using spectrin, purified spectrin-actin complex, or red cell membranes. These experiments demonstrated that the deletion of the Lys residue clearly prevents the binding capacity. Similar results were obtained with a construct containing the Lys residue but lacking Motif I. These data strongly suggest that the binding site to the spectrin-actin complex must contain the Lys 447 (or 448), and therefore resides not only on Motif I but extends 3' of this essential motif.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neuropeptídeos
/
Actinas
/
Espectrina
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Proteínas do Citoesqueleto
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Eliptocitose Hereditária
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Membrana Eritrocítica
/
Proteínas de Membrana
Tipo de estudo:
Risk_factors_studies
Limite:
Female
/
Humans
/
Male
País como assunto:
Europa
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article