Abstract
SAP130 is a component of the SF3b mRNA splicing complex and the STAGA/TFTC transcription complexes. Although SAP130 has been identified to bind CSN through its interaction with the N-terminal half of CSN1, the molecular function of SAP130, in vivo, has remained unclear.
In Arabidopsis, SAP130 is encoded by two genes, AtSAP130a and AtSAP130b, which both map on chromosome 3. The transcripts for both genes were detected in all observed organs. The promoter activity of AtSAP130a and AtSAP130b was detected in similar tissues displaying identical patterns at a specific stage in the developing anther. These data suggest redundant roles of the two genes in vivo. Furthermore, detailed histological analyses revealed that AtSAP130 RNAi mutants show a pollen developmental defect at the microspore stage to the bicellular stage transition, presumably contributing to the reduction of the final seed number. These results revealed that AtSAP130 function is essential for proper pollen development in Arabidopsis.
