Pentatricopeptide repeat protein PHOTOSYSTEM I BIOGENESIS FACTOR2 is required for splicing of ycf3

作  者:Wang XM, Yang ZP, Zhang Y, Zhou W, Zhang AH, Lu CM*
影响因子:4.885
刊物名称:Journal of Integrative Plant Biology
出版年份:2020
卷:  期:  页码:DOI: 10.1111/jipb.12936

论文摘要:

To gain a better understanding of the molecular mechanisms of photosystem I (PSI) biogenesis, we characterized the Arabidopsis thaliana photosystem I biogenesis factor 2 (pbf2 ) mutant, which lacks PSI complex. PBF2 encodes a Pclass pentatricopeptide repeat (PPR) protein. In the pbf2 mutants, we observed a striking decrease in the transcript level of only one gene, the chloroplast gene ycf3 , which is essential for PSI assembly. Further analysis of ycf3 transcripts showed that PBF2 is specifically required for the splicing of ycf3 intron 1. Computational prediction of binding sequences and electrophoretic mobility shift assays reveal that PBF2 specifically binds to a sequence in ycf3 intron 1. Moreover, we found that PBF2 interacted with two general factors for group II intron splicing CHLOROPLAST RNA SPLICING2ASSOCIATED FACTOR1 (CAF1) and CAF2, and facilitated the association of these two factors with ycf3 intron 1. Our results suggest that PBF2 is specifically required for the splicing of ycf3 intron 1 through cooperating with CAF1 and CAF2. Our results also suggest that additional proteins are required to contribute to the specificity of CAFdependent group II intron splicing.