AUTHOR=Obermeyer Simon , Stöckl Richard , Schnekenburger Tobias , Moehle Christoph , Schwartz Uwe , Grasser Klaus D. 

TITLE=Distinct role of subunits of the Arabidopsis RNA polymerase II elongation factor PAF1C in transcriptional reprogramming

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.974625

DOI=10.3389/fpls.2022.974625

ISSN=1664-462X

ABSTRACT=<p>Transcript elongation by RNA polymerase II (RNAPII) is dynamic and highly regulated, thereby contributing to the implementation of gene expression programs during plant development or in response to environmental cues. The heterohexameric polymerase-associated factor 1 complex (PAF1C) stabilizes the RNAPII elongation complex promoting efficient transcript synthesis. In addition, PAF1C links transcriptional elongation with various post-translational histone modifications at transcribed loci. We have exposed <italic>Arabidopsis</italic> mutants deficient in the PAF1C subunits ELF7 or CDC73 to elevated NaCl concentrations to provoke a transcriptional response. The growth of <italic>elf7</italic> plants was reduced relative to that of wildtype under these challenging conditions, whereas <italic>cdc73</italic> plants exhibited rather enhanced tolerance. Profiling of the transcriptional changes upon NaCl exposure revealed that <italic>cdc73</italic> responded similar to wildtype. Relative to wildtype and <italic>cdc73</italic>, the transcriptional response of <italic>elf7</italic> plants was severely reduced in accord with their greater susceptibility to NaCl. The data also imply that CDC73 is more relevant for the transcription of longer genes. Despite the fact that both ELF7 and CDC73 are part of PAF1C the strikingly different transcriptional response of the mutants upon NaCl exposure suggests that the subunits have (partially) specific functions.</p>