Abstract
Serine/arginine-rich (SR) proteins play important roles in constitutive and alternative splicing in animals. They contain an N-terminal RNA recognition motif (RRM) and a C-terminal arginine/serine (RS)-rich domain for protein-protein interaction. We isolated 19 rice cDNAs encoding SR proteins, of which 7 contain plant specific charactaristics. To determine whether SR proteins modulate splicing efficiency and alternative splicing, we used transient assays with rice protoplasts. The results of assays showed that OsSR3, a plant-specific SR protein, enhanced splicing of Wxb intron1. We are also determining binding sequences of each SR protein by using the SELEX method. Transgenic rice overexpressing each of the SR protein gene is being generated and they will be examined for possible changes in alternative splicing of pre-mRNAs in rice.
