AN3 MESSENGER-RNA ENCODES AN RNA HELICASE THAT COLOCALIZES WITH NUCLEOLI IN XENOPUS-OOCYTES IN A STAGE-SPECIFIC MANNER

Citation
R. Gururajan et al., AN3 MESSENGER-RNA ENCODES AN RNA HELICASE THAT COLOCALIZES WITH NUCLEOLI IN XENOPUS-OOCYTES IN A STAGE-SPECIFIC MANNER, Proceedings of the National Academy of Sciences of the United Statesof America, 91(6), 1994, pp. 2056-2060
Citations number
29
Categorie Soggetti
Multidisciplinary Sciences
ISSN journal
00278424
Volume
91
Issue
6
Year of publication
1994
Pages
2056 - 2060
Database
ISI
SICI code
0027-8424(1994)91:6<2056:AMEARH>2.0.ZU;2-E
Abstract
An3 is a maternal mRNA localized to the animal hemisphere of oocytes a nd early embryos. We have analyzed the enzymatic activity and the subc ellular localization of the protein encoded by An3 mRNA during Xenopus oogenesis. Antibodies raised using recombinant full-length and trunca ted An3 protein recognized a single protein in Xenopus and single prot eins from HeLa cells, Drosophila, mouse testes, and Saccharomyces cere visiae. An3 protein immunoprecipitated from stage IV and stage VI oocy tes had ATP-dependent RNA helicase activity. The subcellular location of An3 protein changed during oocyte development. In previtellogenic o ocytes, An3 was present throughout the nucleus; cytoplasmic localizati on was relatively sparse. Nuclear localization in mid-vitellogenic ooc ytes was primarily nucleolar; cytoplasmic staining increased relative to earlier stages. In stage VI oocytes, An3 protein was detected only in the cytoplasm. The temporal change in An3 protein localization is c onsistent with a role in the production of large maternal pools of rRN A during oogenesis.