Structural requirements of 5S rRNA for nuclear transport, 7S ribonucleoprotein particle assembly, and 60S ribosomal subunit assembly in Xenopus oocytes.
Mol Cell Biol
; 13(11): 6819-31, 1993 Nov.
Article
em En
| MEDLINE
| ID: mdl-8413275
ABSTRACT
Structural requirements of 5S rRNA for nuclear transport and RNA-protein interactions have been studied by analyzing the behavior of oocyte-type 5S rRNA and of 31 different in vitro-generated mutant transcripts after microinjection into the cytoplasm of Xenopus oocytes. Experiments reveal that the sequence and secondary and/or tertiary structure requirements of 5S rRNA for nuclear transport, storage in the cytoplasm as 7S ribonucleoprotein particles, and assembly into 60S ribosomal subunits are complex and nonidentical. Elements of loops A, C, and E, helices II and V, and bulged and hinge nucleotides in the central domain of 5S rRNA carry the essential information for these functional activities. Assembly of microinjected 5S rRNA into 60S ribosomal subunits was shown to occur in the nucleus; thus, the first requirement for subunit assembly is nuclear targeting. The inhibitory effects of ATP depletion, wheat germ agglutinin, and chilling on the nuclear import of 5S rRNA indicate that it crosses the nuclear envelope through the nuclear pore complex by a pathway similar to that used by karyophilic proteins.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Ribonucleoproteínas
/
Ribossomos
/
RNA Ribossômico 5S
/
Núcleo Celular
Limite:
Animals
Idioma:
En
Revista:
Mol Cell Biol
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Nova Zelândia