We have isolated over forty U1, U2, U5 and U6snRNA genes from potato and maize. In many cases, the genes are linked. Genes for the SmG core protein and the U1snRNP-, U2snRNP- and U5snRNP-specific proteins, U1A, U2B" and PRP8 have been isolated from various plants. In RNA binding studies, potato U2B" interacted with human U2A' to confer specific and stable binding to U2snRNA, highlighting the degree of conservation of these RNA-binding proteins.

In collaboration with Professor David Meinke, Oklahoma State University, the properties of PRP8 genes in maize and Arabidopsis have been examined. An Arabidopsis PRP8 gene was isolated as a T-DNA insertion mutant, sus2-1. The genes are of interest because they differ in the presence (maize) and absence (Arabidopsis) of proline-rich regions in the N-terminal end, known to be required for function in yeast. In addition, the maize gene contains 23 introns while the Arabidopsis gene contains only 11. In both plants there are 3-4 PRP8 genes, while there is only one in yeast and human.

Simpson et al. (1995) EMBO J. 14, 4540-4550.
Brown and Simpson (1998) Ann. Rev. Plant Physiol. & Plant Mol. Biol. 49, 77-95.