Leucine periodicity of U2 small nuclear ribonucleoprotein particle (snRNP) A' protein is implicated in snRNP assembly via protein-protein interactions.


Journal Article

Recombinant A' protein could be reconstituted into U2 small nuclear ribonucleoprotein particles (snRNPs) upon addition to HeLa cell extracts as determined by coimmunoprecipitation and particle density; however, direct binding to U2 RNA could not be demonstrated except in the presence of the U2 snRNP B" protein. Mutational analysis indicated that a central core region of A' was required for particle reconstitution. This region consists of five tandem repeats of approximately 24 amino acids each that exhibit a periodicity of leucine and asparagine residues that is distinct from the leucine zipper. Similar leucine-rich (Leu-Leu motif) repeats are characteristic of a diverse array of soluble and membrane-associated proteins from yeasts to humans but have not been reported previously to reside in nuclear proteins. Several of these proteins, including Toll, chaoptin, RNase/angiogenin inhibitors, lutropin-choriogonadotropin receptor, carboxypeptidase N, adenylyl cyclase, CD14, and human immunodeficiency virus type 1 Rev, may be involved in protein-protein interactions. Our findings suggest that in cell extracts the Leu-Leu motif of A' is required for reconstitution with U2 snRNPs and perhaps with other components involved in splicing through protein-protein interactions.

Full Text

Duke Authors

Cited Authors

  • Fresco, LD; Harper, DS; Keene, JD

Published Date

  • March 1, 1991

Published In

Volume / Issue

  • 11 / 3

Start / End Page

  • 1578 - 1589

PubMed ID

  • 1825347

Pubmed Central ID

  • 1825347

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/mcb.11.3.1578


  • eng

Conference Location

  • United States