Structure, chromosome location, and expression of the human smooth muscle (enteric type) gamma-actin gene: evolution of six human actin genes.
Mol Cell Biol
; 11(6): 3296-306, 1991 Jun.
Article
en En
| MEDLINE
| ID: mdl-1710027
ABSTRACT
Recombinant phages that carry the human smooth muscle (enteric type) gamma-actin gene were isolated from human genomic DNA libraries. The amino acid sequence deduced from the nucleotide sequence matches those of cDNAs but differs from the protein sequence previously reported at one amino acid position, codon 359. The gene containing one 5' untranslated exon and eight coding exons extends for 27 kb on human chromosome 2. The intron between codons 84 and 85 (site 3) is unique to the two smooth muscle actin genes. In the 5' flanking region, there are several CArG boxes and E boxes, which are regulatory elements in some muscle-specific genes. Hybridization with the 3' untranslated region, which is specific for the human smooth muscle gamma-actin gene, suggests the single gene in the human genome and specific expressions in enteric and aortic tissues. From characterized molecular structures of the six human actin isoform genes, we propose a hypothesis of evolutionary pathway of the actin gene family. A presumed ancestral actin gene had introns at least sites 1, 2, and 4 through 8. Cytoplasmic actin genes may have directly evolved from it through loss of introns at sites 5 and 6. However, through duplication of the ancestral actin gene with substitutions of many amino acids, a prototype of muscle actin genes had been created. Subsequently, striated muscle actin and smooth muscle actin genes may have evolved from this prototype by loss of an intron at site 4 and acquisition of a new intron at site 3, respectively.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cromosomas Humanos Par 2
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Actinas
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Evolución Biológica
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Músculo Liso
Límite:
Animals
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Humans
Idioma:
En
Revista:
Mol Cell Biol
Año:
1991
Tipo del documento:
Article
País de afiliación:
Japón