Arabidopsis CPL4 is an essential C-terminal domain phosphatase that suppresses xenobiotic stress responses

2014-10-01
Fukudome, Akihito
Aksoy, Emre
Wu, Xiaoqiang
Kumar, Krishna
Jeong, In Sil
May, Kimberly
Russell, William K.
Koiwa, Hisashi
© 2014 The Authors.Eukaryotic gene expression is both promoted and inhibited by the reversible phosphorylation of the C-terminal domain of RNA polymerase II (pol II CTD). More than 20 Arabidopsis genes encode CTD phosphatase homologs, including four CTD phosphatase-like (CPL) family members. Although in vitro CTD phosphatase activity has been established for some CPLs, none have been shown to be involved in the phosphoregulation of pol II in vivo. Here we report that CPL4 is a CTD phosphatase essential for the viability of Arabidopsis thaliana. Mass spectrometry analysis identified the pol II subunits RPB1, RPB2 and RPB3 in the affinity-purified CPL4 complex. CPL4 dephosphorylates both Ser2- and Ser5-PO4 of the CTD in vitro, with a preference for Ser2-PO4. Arabidopsis plants overexpressing CPL4 accumulated hypophosphorylated pol II, whereas RNA interference-mediated silencing of CPL4 promoted hyperphosphorylation of pol II. A D128A mutation in the conserved DXDXT motif of the CPL4 catalytic domain resulted in a dominant negative form of CPL4, the overexpression of which inhibited transgene expression in transient assays. Inhibition was abolished by truncation of the phosphoprotein-binding Breast Cancer 1 C-terminal domain of CPL4, suggesting that both catalytic function and protein-protein interaction are essential for CPL4-mediated regulation of gene expression. We were unable to recover a homozygous cpl4 mutant, probably due to the zygotic lethality of this mutation. The reduction in CPL4 levels in CPL4RNAi plants increased transcript levels of a suite of herbicide/ xenobiotic-responsive genes and improved herbicide tolerance, thus suggesting an additional role for CPL4 as a negative regulator of the xenobiotic detoxification pathway.
Plant Journal

Suggestions

Arabidopsis C-Terminal Domain Phosphatase-Like 1 Functions in miRNA Accumulation and DNA Methylation
Jeong, In Sil; Aksoy, Emre; Fukudome, Akihito; Akhter, Salina; Hiraguri, Akihiro; Fukuhara, Toshiyuki; Bahk, Jeong Dong; Koiwa, Hisashi (2013-09-01)
Arabidopsis CTD-PHOSPHATASE-LIKE 1 (CPL1) is a protein phosphatase that can dephosphorylate RNA polymerase II C-terminal domain (CTD). Unlike typical CTD-phosphatases, CPL1 contains a double-stranded (ds) RNA-binding motif (dsRBM) and has been implicated for gene regulation mediated by dsRNA-dependent pathways. We investigated the role of CPL1 and its dsRBMs in various gene silencing pathways. Genetic interaction analyses revealed that cpl1 was able to partially suppress transcriptional gene silencing and D...
Design of a sequence based miRNA clustering method; analysis of fungal miRNAs and host organism target genes
Narcı, Kübra; Akkaya, Mahinur S.; Oğul, Hasan; Department of Bioinformatics (2014)
MicroRNAs are small non-coding RNA molecules which contain 21-25 nucleotides, and function in post transcriptional regulation by inhibiting the translation of mRNA targets. miRNAs typically affect gene regulation by forming composite feed forward circuits (cFFCs) which also comprise a transcription factor (TF) and a target gene. By analyzing these cFFCs, the contribution of miRNAs in altering TF networks can be revealed. These contributions could either be the de-escalation of the target gene repertoire or ...
Integer linear programming based solutions for construction of biological networks
Eren Özsoy, Öykü; Can, Tolga; Department of Health Informatics (2014)
Inference of gene regulatory or signaling networks from perturbation experiments and gene expression assays is one of the challenging problems in bioinformatics. Recently, the inference problem has been formulated as a reference network editing problem and it has been show that finding the minimum number of edit operations on a reference network in order to comply with perturbation experiments is an NP-complete problem. In this dissertation, we propose linear programming based solutions for reconstruction o...
ALCAM (Activated Leukocyte Cell Adhesion Molecule)
Yavuz, Esra; ÖYKEN, MERVE; Erson Bensan, Ayşe Elif (2018-01-01)
ALCAM (Activated Leukocyte Cell Adhesion Molecule), also known as CD166 (cluster of differentiation 166), is a member of a subfamily of immunoglobulin receptors with five immunoglobulin-like domains (VVC2C2C2) in the extracellular domain.
Analysis of motifs in microRNA-transcription factor gene regulatory networks
Sürün, Bilge; Acar, Aybar Can; Purutçuoğlu Gazi, Vilda; Department of Bioinformatics (2014)
MicroRNAs are small non-coding RNA molecules which contain 21-25 nucleotides, and function in post transcriptional regulation by inhibiting the translation of mRNA targets. miRNAs typically affect gene regulation by forming composite feed forward circuits (cFFCs) which also comprise a transcription factor (TF) and a target gene. By analyzing these cFFCs, the contribution of miRNAs in altering TF networks can be revealed. These contributions could either be the de-escalation of the target gene repertoire or ...
Citation Formats
A. Fukudome et al., “Arabidopsis CPL4 is an essential C-terminal domain phosphatase that suppresses xenobiotic stress responses,” Plant Journal, vol. 80, no. 1, pp. 27–39, 2014, Accessed: 00, 2022. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84924861948&origin=inward.