The novel heme-dependent inducible protein, SRRD regulates heme biosynthesis and circadian rhythms

In order to investigate the function of heme in the regulation of gene expression, we herein examined variations in mRNA levels in ALA-treated cells from control conditions. A comprehensive anal- ysis by RNA sequencing showed marked changes in the expression of various genes. Among the different amounts of mRNA, we identified the novel heme-inducible protein, SRRD. The plant ho- mologue Sensitivity to Red Light Reduced (SRR1) was previously reported to be involved in the regulation of the circadian clock and phytochrome B signaling in Arabidopsis thaliana. We found that SRRD regulated not only heme biosynthesis, but also the expression of clock genes. The involvement of SRRD in the prolif- eration of cells was also demonstrated. Overall design: Examination of ALA-treated versus untreated NIH3T3 cells.