Dynamic expression of three “RNA processing and modification” Genes of Phanerochaete Chrysosporium under Pb stress

Tekin, Elif
RNA-binding proteins (RBP) shuttle between cellular compartments either constitutively or in response to stress and regulate localization, translation and turn over of mRNAs. In our laboratory, cytosolic proteome map of Phanerochaete chrysosporium was established and upon Pb exposure, the changes in cytosolic protein expressions were determined. The identified RBPs were a newly induced polyadenylate-binding protein (RRM superfamily) as well as two up-regulated proteins, namely splicing factor RNPS1 and ATP-dependent RNA helicase, all being very important candidates of post-transcriptional control in response to stress. This finding inspired us to conduct Real Time PCR studies in order to have a better understanding of the changes in the expression of corresponding genes at mRNA level in response to Pb exposure, thus the present study aims at examining the effect of lead exposure on the transcript levels of the genes coding for ATP-dependent RNA helicase, splicing factor RNPS1 and polyadenylate binding protein. As shown via expression analysis based on Real Time PCR, the mRNA level of splicing factor RNPS1 showed 2.68, 2.62 and 4.86 fold increases in a dose-dependent manner when the cells were grown for 40 h in the presence of 25, 50 and 100 µM Pb, repectively. ATP-dependent RNA helicase mRNA level showed no significant increase in response to 25 µM Pb exposure while increased 2 and 1.84 fold in response to 50 and 100 µM Pb, respectively. Polyadenylate binding protein mRNA levels revealed no significant increase when exposed to 25, 50 and 100 µM Pb. As to the mRNA dynamics as a function of duration of lead exposure, the mRNA level of this protein showed 2.54-fold increase upon 1 h exposure to 100 µM Pb. Splicing factor RNPS1 mRNA level showed a significant increase of 19.22 fold at 2nd h of 50 µM Pb exposure. Expression level of ATP-dependent RNA helicase was not affected by the time of exposure to Pb.
Citation Formats
E. Tekin, “Dynamic expression of three “RNA processing and modification” Genes of Phanerochaete Chrysosporium under Pb stress,” M.S. - Master of Science, Middle East Technical University, 2011.