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Citation
Labourier, E., Rio, D.C. (2001). Purification of Drosophila snRNPs and characterization of two populations of functional U1 particles.  RNA 7(3): 457--470.
FlyBase ID
FBrf0135940
Publication Type
Research paper
Abstract

U1 snRNP is required at an early stage during assembly of the spliceosome, the dynamic ribonucleoprotein (RNP) complex that performs nuclear pre-mRNA splicing. Here, we report the purification of U1 snRNP particles from Drosophila nuclear extracts and the characterization of their biochemical properties, polypeptide contents, and splicing activities. On the basis of their antigenicity, apparent molecular weight, and by peptide sequencing, the Drosophila 70K, SNF, B, U1-C, D1, D2, D3, E, F, and G proteins are shown to be integral components of these particles. Sequence database searches revealed that both the U1-specific and the Sm proteins are extensively conserved between human and Drosophila snRNPs. Furthermore, both species possess a conserved intrinsic U1-associated kinase activity with identical substrate specificity in vitro. Finally, our results demonstrate that a second type of functional U1 particle, completely lacking the U1/U2-specific protein SNF and the associated protein kinase activity, can be isolated from cultured Kc cell or Canton S embryonic nuclear extracts. This work describes the first characterization of a purified Drosophila snRNP particle and reinforces the view that their activity and composition, with the exception of the atypical bifunctional U1-A/U2-B" SNF protein, are highly conserved in metazoans.

PubMed ID
PubMed Central ID
PMC1370101 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    RNA
    Title
    RNA (New York, N.Y.)
    Publication Year
    1995-
    ISBN/ISSN
    1355-8382
    Data From Reference