@article{ZhangRammingHeinkeetal.2019,
  author    = {Zhang, Yunming and Ramming, Anna and Heinke, Lisa and Altschmied, Lothar and Slotkin, R. Keith and Becker, J{\"o}rg D. and Kappel, Christian and Lenhard, Michael},
  title     = {The poly(A) polymerase PAPS1 interacts with the RNA-directed DNA-methylation pathway in sporophyte and pollen development},
  series = {The plant journal},
  volume    = {99},
  journal   = {The plant journal},
  number    = {4},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.14348},
  pages     = {655 -- 672},
  year      = {2019},
  abstract  = {RNA-based processes play key roles in the regulation of eukaryotic gene expression. This includes both the processing of pre-mRNAs into mature mRNAs ready for translation and RNA-based silencing processes, such as RNA-directed DNA methylation (RdDM). Polyadenylation of pre-mRNAs is one important step in their processing and is carried out by three functionally specialized canonical nuclear poly(A) polymerases in Arabidopsis thaliana. Null mutations in one of these, termed PAPS1, result in a male gametophytic defect. Using a fluorescence-labelling strategy, we have characterized this defect in more detail using RNA and small-RNA sequencing. In addition to global defects in the expression of pollen-differentiation genes, paps1 null-mutant pollen shows a strong overaccumulation of transposable element (TE) transcripts, yet a depletion of 21- and particularly 24-nucleotide-long short interfering RNAs (siRNAs) and microRNAs (miRNAs) targeting the corresponding TEs. Double-mutant analyses support a specific functional interaction between PAPS1 and components of the RdDM pathway, as evident from strong synergistic phenotypes in mutant combinations involving paps1, but not paps2 paps4, mutations. In particular, the double-mutant of paps1 and rna-dependent rna polymerase 6 (rdr6) shows a synergistic developmental phenotype disrupting the formation of the transmitting tract in the female gynoecium. Thus, our findings in A. thaliana uncover a potentially general link between canonical poly(A) polymerases as components of mRNA processing and RdDM, reflecting an analogous interaction in fission yeast.},
  language  = {en}
}
@phdthesis{Ramming2019,
  author    = {Ramming, Anna},
  title     = {Specific Roles of POLY(A) POLYMERASE1 in the male Gametophyte and Beyond},
  school      = {Universit{\"a}t Potsdam},
  pages     = {143},
  year      = {2019},
  language  = {en}
}
@article{KappelTrostCzesnicketal.2015,
  author    = {Kappel, Christian and Trost, Gerda and Czesnick, Hj{\"o}rdis and Ramming, Anna and Kolbe, Benjamin and Vi, Son Lang and Bispo, Claudia and Becker, J{\"o}rg D. and de Moor, Cornelia and Lenhard, Michael},
  title     = {Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A) Polymerases in Arabidopsis thaliana},
  series = {PLoS Genetics : a peer-reviewed, open-access journal},
  volume    = {11},
  journal   = {PLoS Genetics : a peer-reviewed, open-access journal},
  number    = {8},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1553-7390},
  doi       = {10.1371/journal.pgen.1005474},
  pages     = {30},
  year      = {2015},
  abstract  = {The poly(A) tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A)-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A)-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A)-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A)-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A)-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.},
  language  = {en}
}
@article{KappelTrostCzesnicketal.2015,
  author    = {Kappel, Christian and Trost, Gerda and Czesnick, Hj{\"o}rdis and Ramming, Anna and Kolbe, Benjamin and Vi, Son Lang and Bispo, Cl{\´a}udia and Becker, J{\"o}rg D. and de Moor, Cornelia and Lenhard, Michael},
  title     = {Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A) Polymerases in Arabidopsis thaliana},
  series = {PLoS Genetics : a peer-reviewed, open-access journal},
  volume    = {11},
  journal   = {PLoS Genetics : a peer-reviewed, open-access journal},
  number    = {8},
  publisher = {Public Library of Science},
  address   = {San Francisco},
  issn      = {1553-7390},
  doi       = {10.1371/journal.pgen.1005474},
  pages     = {30},
  year      = {2015},
  abstract  = {The poly(A) tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A)-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A)-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A)-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A)-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A)-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.},
  language  = {en}
}