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Structure and diversity of the T-cell receptor alpha chain in the Mexican axolotl.
Fellah, J S; Kerfourn, F; Dumay, A M; Aubet, G; Charlemagne, J.
Afiliación
  • Fellah JS; Groupe d'Immunologie Comparée, CNRS (UA 1135), Université Pierre et Marie Curie, boite 29, 9 quai Saint-Bernard, 75252 Paris Cedex 05, France.
Immunogenetics ; 45(4): 235-41, 1997.
Article en En | MEDLINE | ID: mdl-9002443
ABSTRACT
Polymerase chain reaction was used to isolate cDNA clones encoding putative T-cell receptor (TCR) alpha chains in an amphibian, the Mexican axolotl (Ambystoma mexicanum). Five TCRalpha-V chain-encoding segments were identified, each belonging to a separate family. The best identity scores for these axolotl TCRalpha-V segments were all provided by sequences belonging to the human TCRalpha-V1 family and the mouse TCRalpha-V3 and TCRalpha-V8 families. A total of 14 different TCRA-J segments were identified from 44 TCRA-V/TCRA-J regions sequenced, suggesting that a large repertoire of TCRA-J segments is a characteristic of most vertebrates. The structure of the axolotl CDR3 alpha chain loop is in good agreement with that of mammals, including a majority of small hydrophobic residues at position 92 and of charged, hydrophilic, or polar residues at positions 93 and 94, which are highly variable and correspond to the TCRA-V/J junction. This suggests that some positions of the axolotl CDR3 alpha chain loop are positively selected during T-cell differentiation, particularly around residue 93 that could be selected for its ability to makes contacts with major histocompatibility complex-associated antigenic peptides, as in mammals. The axolotl Calpha domain had the typical structure of mammalian and avian Calpha domains, including the charged residues in the TM segment that are thought to interact with other proteins in the membrane, as well as most of the residues forming the conserved antigen receptor transmembrane motif.
Asunto(s)
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Variación Genética / Receptores de Antígenos de Linfocitos T alfa-beta Tipo de estudio: Prognostic_studies Límite: Animals / Humans País/Región como asunto: Mexico Idioma: En Revista: Immunogenetics Año: 1997 Tipo del documento: Article País de afiliación: Francia
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Variación Genética / Receptores de Antígenos de Linfocitos T alfa-beta Tipo de estudio: Prognostic_studies Límite: Animals / Humans País/Región como asunto: Mexico Idioma: En Revista: Immunogenetics Año: 1997 Tipo del documento: Article País de afiliación: Francia