SIGNATURE WORK
CONFERENCE & EXHIBITION 2022

Defective Chloroplasts and Leaves (DCL or DeCL) is a gene found at the chloroplast specifically regulating ribosomal plastid RNA processing and embryogenesis. Surprisingly, a homolog of this protein is discovered later at the C-terminal end of RNA polymerases IV and V, the polymerases unique to plants. The domain is shown connected to transcription-level gene silencing in the complex system formed from RNA Polymerase IV and V. This suggests a functionally evolutionary relationship between DCL protein in RNA polymerases and in the chloroplast. However, the biochemical role of DCL is missing from empirical studies. Recombinant DCL and DCL-homologs were constructed and purified in this study. Electrophoretic mobility shift assay (EMSA) was used to investigate the interactions between DCL and other biomolecules like nucleic acids. My results suggested potential non-specific nuclease reactivity of one DCL-homolog in Bacteria because increasing degradation of RNAs was observed in samples with more proteins. This could imply DCL’s role in the processing of RNAs in Pol IV&V’s activity. However, further experiments are needed to exclude the possibility of RNase contamination. Meanwhile, it is still unknown whether the homologs in Pol IV&V have the same biochemical function. Due to persistent impurity after purification, other homologs of DCL did not proceed to biochemical assays. The discovery of this link can have research and agricultural benefits to society by contributing to the evolutionary insight of plants’ gene regulatory system.