Duplication of primate and rodent B7-H3 immunoglobulin V- and C-like domains: divergent history of functional redundancy and exon loss.
Genomics
; 82(3): 365-77, 2003 Sep.
Article
en En
| MEDLINE
| ID: mdl-12906861
ABSTRACT
B7-H3 is a novel protein structurally related to the B7 family of ligands by the presence of a single set of immunoglobulin-V-like and immunoglobulin-C-like (VC) domains. By multiplex PCR, the dominantly expressed form of human B7-H3 was found to be a splice variant containing tandemly duplicated VC domains (VCVC). In contrast, mouse B7-H3 cDNA contained only one single VC form due to an exon structure corresponding to V-(pseudoexon C)-(pseudoexon V)-C. Comparisons of human, monkey, mouse, and hamster genomic B7-H3 reveal that primates, but not rodents, exhibited a higher degree of intramolecular sequence similarity between VC duplications than between molecules. Both VC and VCVC forms of human B7-H3 inhibited CD4(+) T cell proliferation and downregulated cytokine production upon TCR activation. These results suggest independent, but convergent, paths of B7-H3 active domain duplication followed by divergent histories of exon degeneration in rodents and exon maintenance by humans.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Región Variable de Inmunoglobulina
/
Regiones Constantes de Inmunoglobulina
/
Antígeno B7-1
/
Evolución Molecular
/
Duplicación de Gen
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Genomics
Asunto de la revista:
GENETICA
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos