Differential Splicing and Utilization of Non-Canonical Splice Sites by two Novel Arginine/Serine-Rich (SR) Proteins in Maize

GUPTA S, WANG BB, STRIKER GA, ZANETTI ME, LAL S

BIOCHIMICA ET BIOPHYSICA ACTA, N. GENE STRUCTURE AND EXPRESSION

Año: 2005 vol. 1728 p. 105 - 114

0167-4781

The serine-arginine (SR)-rich splicing proteins are highly conserved RNA binding nuclear phosphor-proteins that play important roles in both regular and alternative splicing. Here we describe two novel putative SR genes from maize, designated zmRSp31A and zmRSp31B. Both genes contain characteristic RNA binding motifs RNP-1 and RNP-2, a serine/arginine-rich (RS) domain and share significant sequence similarity to the Arabidopsis atRSp31 family of SR proteins. Both zmRSp31A and zmRSp31B produce multiple transcripts by alternative splicing, of which majority of the alternatively spliced transcripts utilize non-canonical splice sites. zmRSp31A and zmRSp31B produce at least six and four transcripts, respectively, of which only one corresponds to the wild type proteins for each gene. All the alternatively spliced transcripts of both the genes, with one exception, are predicted to encode small truncated proteins containing only the RNP-2 domain of their first RNA recognition motif and completely lack the carboxyl terminal RS domain. We provide evidence that some of the alternatively spliced transcripts of both genes are associated with polysomes and interact with the translational machinery.