Control of SERCA2a Ca2+ pump mRNA stability by nuclear proteins: role of domains in the 3'-untranslated region.
Cell Calcium
; 37(1): 17-24, 2005 Jan.
Article
em En
| MEDLINE
| ID: mdl-15541460
ABSTRACT
Alternative splicing of the sarco/endoplasmic reticulum (SERCA2) Ca2+ pump transcript generates the two isoforms SERCA2a in left ventricular myocytes (LVM) and SERCA2b in most tissues. Nuclear protein extracts from left ventricular myocytes can cause a decay of the 3'-region of the SERCA2a. To determine if all the domains in the 800 b SERCA2a 3'-end region (3344-4243) are equally stable, we examined in vitro decay of synthetically capped, polyadenylated overlapping RNA fragments 2A1-2A6 from the 3'-end region of SERCA2a. Whereas 2A1-2A5 RNAs were stable, the distal fragment 2A6 (4135-4243 b) decayed rapidly. Deleting the 2A6 sequence from the 800-b 3'-end region increased its stability. In mobility shift assays, 2A6 bound to protein(s) in the LVM nuclear extracts in a specific manner unlabelled 2A6 or the 800 b 3'-region RNA competed for binding but poly A, poly U, and poly C RNA did not. Secondary structure analysis revealed three hairpin loops in 2A6. Experiments using small synthetic RNA fragments for competition with 2A6 binding to nuclear proteins were consistent with a model involving the three hairpin loops. Thus, the secondary structure of the distal domain of SERCA2a RNA may be important in regulating its stability.
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Base de dados:
MEDLINE
Assunto principal:
RNA Mensageiro
/
Proteínas Nucleares
/
ATPases Transportadoras de Cálcio
/
Regiões 3' não Traduzidas
/
Estabilidade de RNA
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article