RNA Polymerase II C-Terminal Domain Phosphatase-Like 1 (CPL1) Arabidopsis Thaliana Recombinant Protein

encodes a a novel transcriptional repressor harboring two double-stranded RNA-binding domains and a region homologous to the catalytic domain of RNA polymerase II C-terminal domain phosphatases found in yeast and in animals that regulate gene transcription. Protein exhibits innate phosphatase activity in vitro. Mutants exhibit hyperresponsiveness to ABA, cold, and NaCl.

Processively dephosphorylates 'Ser-5' but not 'Ser-2' of the heptad repeats YSPTSPS in the C-terminal domain of the largest RNA polymerase II subunit (RPB1). This promotes the activity of RNA polymerase II. Together with CPL2, required for male gametes fertility. Multifunctional regulator that modulates plant growth, stress, and phytohormones responses. Negative regulator of stress gene transcription involved in abscisic acid (ABA) mediated and jasmonic acid (JA) mediated signaling pathways, NaCl, osmotic stress, wounding, and cold resistance. Regulates negatively the expression of jasmonic acid (JA) biosynthetic genes in response to wounding (PubMed:11874572, PubMed:12149434, PubMed:12149453, PubMed:15388846, PubMed:18506580, PubMed:18764923). Forms a complex with RCF3 that modulates co-transcriptional processes such as mRNA capping and polyadenylation, and functions to repress stress-inducible gene expression (PubMed:23874224). Dephosphorylates RCF3 (PubMed:26227967). Involved in the dephosphorylation of EIF4A3. This dephosphorylation retains EIF4A3 in the nucleus and limits its accumulation in the cytoplasm. Is essential for the degradation of the nonsense-mediated mRNA decay (NMD) transcripts (PubMed:26887918).