miR-122, a mammalian liver-specific microRNA, is processed from hcr mRNA and may downregulate the high affinity cationic amino acid transporter CAT-1.
RNA Biol
; 1(2): 106-13, 2004 Jul.
Article
en En
| MEDLINE
| ID: mdl-17179747
ABSTRACT
These studies show that miR-122, a 22-nucleotide microRNA, is derived from a liver-specific noncoding polyadenylated RNA transcribed from the gene hcr. The exact sequence of miR-122 as well as the adjacent secondary structure within the hcr mRNA are conserved from mammalian species back to fish. Levels of miR-122 in the mouse liver increase to half maximal values around day 17 of embryogenesis, and reach near maximal levels of 50,000 copies per average cell before birth. Lewis et al. (2003) predicted the cationic amino acid transporter (CAT-1 or SLC7A1) as a miR-122 target. CAT-1 protein and its mRNA are expressed in all mammalian tissues but with lower levels in adult liver. Furthermore, during mouse liver development CAT-1 mRNA decreases in an almost inverse correlation with miR-122. Eight potential miR-122 target sites were predicted within the human CAT-1 mRNA, with six in the 3'-untranslated region. Using a reporter construct it was found that just three of the predicted sites, linked in a 400-nucleotide sequence from human CAT-1, acted with synergy and were sufficient to strongly inhibit protein synthesis and reduce mRNA levels. In summary, these studies followed the accumulation during development of miR-122 from its mRNA precursor, hcr, through to identification of what may be a specific mRNA target, CAT-1.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Regulación hacia Abajo
/
Procesamiento Postranscripcional del ARN
/
Transportador de Aminoácidos Catiónicos 1
/
Poliadenilación
/
MicroARNs
/
Péptidos y Proteínas de Señalización Intracelular
Límite:
Animals
/
Humans
Idioma:
En
Revista:
RNA Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos