Telomerase-reverse transcriptase (TERT) plays an essential catalytic role in maintaining telomeres. However, in animal systems telomerase plays additional non-telomeric functional roles. We previously screened an Arabidopsis cDNA library for proteins that interact with the C-terminal extension (CTE) TERT domain and identified a nuclear-localized protein that contains an RNA recognition motif (RRM). This RRM-protein forms homodimers in both plants and yeast. Mutation of the gene encoding the RRM-protein had no detectable effect on plant growth and development, nor did it affect telomerase activity or telomere length in vivo, suggesting a non-telomeric role for TERT/RRM-protein complexes. The gene encoding the RRM-protein is highly expressed in leaf and reproductive tissues. We further screened an Arabidopsis cDNA library for proteins that interact with the RRM-protein and identified five interactors. These proteins are involved in numerous non-telomere-associated cellular activities. In plants, the RRM-protein, both alone and in a complex with its interactors, localizes to nuclear speckles. Transcriptional analyses in wild-type and rrm mutant plants, as well as transcriptional co-analyses, suggest that TERT, the RRM-protein, and the RRM-protein interactors may play important roles in non-telomeric cellular functions.

Department of Biological Sciences Purdue University West Lafayette IN USA

Institute of Experimental Botany Academy of Sciences of the Czech Republic v v i Prague Czech Republic

Mendel Centre for Plant Genomics and Proteomics Central European Institute of Technology and Faculty of Science Masaryk University Brno Czech Republic ; Institute of Biophysics Academy of Sciences of the Czech Republic v v i Brno Czech Republic

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Amiard S., Da Ines O., Gallego M. E., White C. I. (2014). Responses to telomere erosion in plants. PLoS ONE 9:e86220 10.1371/journal.pone.0086220 PubMed DOI PMC

Arabidopsis Interactome Mapping Consortium. Dreze M., Carvunis A., Charloteaux B., Galli M., Pevzner S., et al. (2011). Evidence for network evolution in an Arabidopsis interactome map. Science 333 601–607. 10.1126/science.1203877 PubMed DOI PMC

Askree S. H., Yehuda T., Smolikov S., Gurevich R., Hawk J., Coker C., et al. (2004). A genome-wide screen for Saccharomyces cerevisiae deletion mutants that affect telomere length. Proc. Natl. Acad. Sci. U.S.A. 101 8658–8663. 10.1073/pnas.0401263101 PubMed DOI PMC

Blasco M. A. (2005). Mice with bad ends: mouse models for the study of telomeres and telomerase in cancer and aging. EMBO J. 24 1095–1103. 10.1038/sj.emboj.7600598 PubMed DOI PMC

Calado A., Carmo-Fonseca M. (2000). Localization of poly(A)-binding protein 2 (PABP2) in nuclear speckles is independent of import into the nucleus and requires binding to poly(A) RNA. J. Cell Sci. 113(Pt 12) 2309–2318. PubMed

Citovsky V., Lee L.-Y., Vyas S., Glick E., Chen M. H., Vainstein A., et al. (2006). Subcellular localization of interacting proteins by bimolecular fluorescence complementation in planta. J. Mol. Biol. 362 1120–1131. 10.1016/j.jmb.2006.08.017 PubMed DOI

Counter C. M., Avilion A. A., Lefeuvre C. E., Stewart N. G., Greider C. W., Harley C. B., et al. (1992). Telomere shortening associated with chromosome instability is arrested in immortal cells which express telomerase activity. EMBO J. 11 1921–1929. PubMed PMC

Deo R. C., Bonanno J. B., Sonenberg N., Burley S. K. (1999). Recognition of polyadenylate RNA by the poly(A)-binding protein. Cell 98 835–845. 10.1016/S0092-8674(00)81517-2 PubMed DOI

Domingues M. N., Sforca M. L., Soprano A. S., Lee J., De Souza Tde A., Cassago A., et al. (2015). Structure and mechanism of dimer-monomer transition of a plant poly(A)-binding protein upon RNA interaction: insights into its poly(A) tail assembly. J. Mol. Biol. 427 2491–2506. 10.1016/j.jmb.2015.05.017 PubMed DOI

Eliseeva I. A., Lyabin D. N., Ovchinnikov L. P. (2013). Poly(A)-binding proteins: structure, domain organization, and activity regulation. Biochemistry Mosc. 78 1377–1391. 10.1134/S0006297913130014 PubMed DOI

Fitzgerald M. S., Mcknight T. D., Shippen D. E. (1996). Characterization and developmental patterns of telomerase expression in plants. Proc. Natl. Acad. Sci. U.S.A. 93 14422–14427. 10.1073/pnas.93.25.14422 PubMed DOI PMC

Fojtova M., Peska V., Dobsakova Z., Mozgova I., Fajkus J., Sykorova E. (2011). Molecular analysis of T-DNA insertion mutants identified putative regulatory elements in the AtTERT gene. J. Exp. Bot. 62 5531–5545. 10.1093/jxb/err235 PubMed DOI PMC

Gaspin C., Rami J. F., Lescure B. (2010). Distribution of short interstitial telomere motifs in two plant genomes: putative origin and function. BMC Plant Biol. 10:283 10.1186/1471-2229-10-283 PubMed DOI PMC

Gatbonton T., Imbesi M., Nelson M., Akey J. M., Ruderfer D. M., Kruglyak L., et al. (2006). Telomere length as a quantitative trait: genome-wide survey and genetic mapping of telomere length-control genes in yeast. PLoS Genet. 2:e35 10.1371/journal.pgen.0020035 PubMed DOI PMC

Ge H., Zhou D., Tong S., Gao Y., Teng M., Niu L. (2008). Crystal structure and possible dimerization of the single RRM of human PABPN1. Proteins 71 1539–1545. 10.1002/prot.21973 PubMed DOI

Gohring J., Fulcher N., Jacak J., Riha K. (2014). TeloTool: a new tool for telomere length measurement from terminal restriction fragment analysis with improved probe intensity correction. Nucleic Acids Res. 42:e21 10.1093/nar/gkt1315 PubMed DOI PMC

Greider C. W., Blackburn E. H. (1985). Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. Cell 43 405–413. 10.1016/0092-8674(85)90170-9 PubMed DOI

Greider C. W., Blackburn E. H. (1987). The telomere terminal transferase of Tetrahymena is a ribonucleoprotein enzyme with two kinds of primer specificity. Cell 51 887–898. 10.1016/0092-8674(87)90576-9 PubMed DOI

Harley C. B., Futcher A. B., Greider C. W. (1990). Telomeres shorten during ageing of human fibroblasts. Nature 345 458–460. 10.1038/345458a0 PubMed DOI

Honys D., Twell D. (2004). Transcriptome analysis of haploid male gametophyte development in Arabidopsis. Genome Biol. 5:R85 10.1186/gb-2004-5-11-r85 PubMed DOI PMC

Hruz T., Laule O., Sza bo G., Wessendorp F., Bleuler S., Oertle L., et al. (2008). Genevestigator v3: a reference expression database for the meta-analysis of transcriptomes. Adv. Bioinformatics 2008:420747 10.1155/2008/420747 PubMed DOI PMC

Jung C., Seo J. S., Han S. W., Koo Y. J., Kim C. H., Song S. I., et al. (2008). Overexpression of AtMYB44 enhances stomatal closure to confer abiotic stress tolerance in transgenic Arabidopsis. Plant Physiol. 146 623–635. 10.1104/pp.107.110981 PubMed DOI PMC

Keller R. W., Kuhn U., Aragon M., Bornikova L., Wahle E., Bear D. G. (2000). The nuclear poly(A) binding protein, PABP2, forms an oligomeric particle covering the length of the poly(A) tail. J. Mol. Biol. 297 569–583. 10.1006/jmbi.2000.3572 PubMed DOI

Kim M. H., Sonoda Y., Sasaki K., Kaminaka H., Imai R. (2013). Interactome analysis reveals versatile functions of Arabidopsis COLD SHOCK DOMAIN PROTEIN 3 in RNA processing within the nucleus and cytoplasm. Cell Stress Chaperones 18 517–525. 10.1007/s12192-012-0398-3 PubMed DOI PMC

Krietsch J., Rouleau M., Pic E., Ethier C., Dawson T. M., Dawson V. L., et al. (2013). Reprogramming cellular events by poly(ADP-ribose)-binding proteins. Mol. Aspects Med. 34 1066–1087. 10.1016/j.mam.2012.12.005 PubMed DOI PMC

Kuhn U., Gundel M., Knoth A., Kerwitz Y., Rudel S., Wahle E. (2009). Poly(A) tail length is controlled by the nuclear poly(A)-binding protein regulating the interaction between poly(A) polymerase and the cleavage and polyadenylation specificity factor. J. Biol. Chem. 284 22803–22814. 10.1074/jbc.M109.018226 PubMed DOI PMC

Kwon C., Chung I. K. (2004). Interaction of an Arabidopsis RNA-binding protein with plant single-stranded telomeric DNA modulates telomerase activity. J. Biol. Chem. 279 12812–12818. 10.1074/jbc.M312011200 PubMed DOI

Lee L.-Y., Wu F. H., Hsu C. T., Shen S. C., Yeh H. Y., Liao D. C., et al. (2012). Screening a cDNA library for protein-protein interactions directly in planta. Plant Cell 24 1746–1759. 10.1105/tpc.112.097998 PubMed DOI PMC

Levy M. Z., Allsopp R. C., Futcher A. B., Greider C. W., Harley C. B. (1992). Telomere end-replication problem and cell aging. J. Mol. Biol. 225 951–960. 10.1016/0022-2836(92)90096-3 PubMed DOI

Loreni F., Mancino M., Biffo S. (2014). Translation factors and ribosomal proteins control tumor onset and progression: how? Oncogene 33 2145–2156. 10.1038/onc.2013.153 PubMed DOI

Lorkovic Z. J., Hilscher J., Barta A. (2004). Use of fluorescent protein tags to study nuclear organization of the spliceosomal machinery in transiently transformed living plant cells. Mol. Biol. Cell 15 3233–3243. 10.1091/mbc.E04-01-0055 PubMed DOI PMC

Majerska J., Sykorova E., Fajkus J. (2011). Non-telomeric activities of telomerase. Mol. Biosyst. 7 1013–1023. 10.1039/c0mb00268b PubMed DOI

Manevski A., Bertoni G., Bardet C., Tremousaygue D., Lescure B. (2000). In synergy with various cis-acting elements, plant insterstitial telomere motifs regulate gene expression in Arabidopsis root meristems. FEBS Lett. 483 43–46. 10.1016/S0014-5793(00)02056-1 PubMed DOI

Ogrocka A., Sykorova E., Fajkus J., Fojtova M. (2012). Developmental silencing of the AtTERT gene is associated with increased H3K27me3 loading and maintenance of its euchromatic environment. J. Exp. Bot. 63 4233–4241. 10.1093/jxb/ers107 PubMed DOI PMC

Olovnikov A. M. (1971). [Principle of marginotomy in template synthesis of polynucleotides]. Dokl. Akad. Nauk. SSSR 201 1496–1499. PubMed

Olovnikov A. M. (1973). A theory of marginotomy. The incomplete copying of template margin in enzymic synthesis of polynucleotides and biological significance of the phenomenon. J. Theor. Biol. 41 181–190. 10.1016/0022-5193(73)90198-7 PubMed DOI

Pfaffl M. W. (2004). “Quantification strategies in real-time PCR,” in A-Z of Quantitative PCR ed. Bustin S. A. (La Jolla, CA: International University Line; ) 87–112.

Regad F., Lebas M., Lescure B. (1994). Interstitial telomeric repeats within the Arabidopsis thaliana genome. J. Mol. Biol. 239 163–169. 10.1006/jmbi.1994.1360 PubMed DOI

Schrumpfová P. P., Vychodilova I., Dvorackova M., Majerska J., Dokladal L., Schorova S., et al. (2014). Telomere repeat binding proteins are functional components of Arabidopsis telomeres and interact with telomerase. Plant J. 77 770–781. 10.1111/tpj.12428 PubMed DOI PMC

Seimiya H., Sawada H., Muramatsu Y., Shimizu M., Ohko K., Yamane K., et al. (2000). Involvement of 14-3-3 proteins in nuclear localization of telomerase. EMBO J. 19 2652–2661. 10.1093/emboj/19.11.2652 PubMed DOI PMC

Song J., Mcgivern J. V., Nichols K. W., Markley J. L., Sheets M. D. (2008). Structural basis for RNA recognition by a type II poly(A)-binding protein. Proc. Natl. Acad. Sci. U.S.A. 105 15317–15322. 10.1073/pnas.0801274105 PubMed DOI PMC

Sykorova E., Fajkus J. (2009). Structure-function relationships in telomerase genes. Biol. Cell 101 375–392. 10.1042/BC20080205 PubMed DOI

Szklarczyk D., Franceschini A., Wyder S., Forslund K., Heller D., Huerta-Cepas J., et al. (2015). STRING v10: protein-protein interaction networks, integrated over the tree of life. Nucleic Acids Res. 43 D447–D452. 10.1093/nar/gku1003 PubMed DOI PMC

Tenea G. N., Spantzel J., Lee L.-Y., Zhu Y., Lin K., Johnson S. J., et al. (2009). Overexpression of several Arabidopsis histone genes increases Agrobacterium-mediated transformation and transgene expression in plants. Plant Cell 21 3350–3367. 10.1105/tpc.109.070607 PubMed DOI PMC

Tremousaygue D., Manevski A., Bardet C., Lescure N., Lescure B. (1999). Plant interstitial telomere motifs participate in the control of gene expression in root meristems. Plant J. 20 553–561. 10.1046/j.1365-313X.1999.00627.x PubMed DOI

Ungar L., Yosef N., Sela Y., Sharan R., Ruppin E., Kupiec M. (2009). A genome-wide screen for essential yeast genes that affect telomere length maintenance. Nucleic Acids Res. 37 3840–3849. 10.1093/nar/gkp259 PubMed DOI PMC

Wahle E., Ruegsegger U. (1999). 3’-End processing of pre-mRNA in eukaryotes. FEMS Microbiol. Rev. 23 277–295. 10.1016/S0168-6445(99)00008-X PubMed DOI

Wang J., Wang Y., Wang Z., Liu L., Zhu X. G., Ma X. (2011). Synchronization of cytoplasmic and transferred mitochondrial ribosomal protein gene expression in land plants is linked to Telo-box motif enrichment. BMC Evol. Biol. 11:161 10.1186/1471-2148-11-161 PubMed DOI PMC

Watson J. D. (1972). Origin of concatemeric T7 DNA. Nat. New Biol. 239 197–201. 10.1038/newbio239197a0 PubMed DOI

Wu F. H., Shen S. C., Lee L.-Y., Lee S. H., Chan M. T., Lin C. S. (2009). Tape-Arabidopsis sandwich - a simpler Arabidopsis protoplast isolation method. Plant Methods 5:16 10.1186/1746-4811-5-16 PubMed DOI PMC

Yamada K., Lim J., Dale J. M., Chen H., Shinn P., Palm C. J., et al. (2003). Empirical analysis of transcriptional activity in the Arabidopsis genome. Science 302 842–846. 10.1126/science.1088305 PubMed DOI

Zachova D., Fojtova M., Dvorackova M., Mozgova I., Lermontova I., Peska V., et al. (2013). Structure-function relationships during transgenic telomerase expression in Arabidopsis. Physiol. Plant 149 114–126. 10.1111/ppl.12021 PubMed DOI

Zhang W. K., Shen Y. G., He X. J., Du B. X., Xie Z. M., Luo G. Z., et al. (2005). Characterization of a novel cell cycle-related gene from Arabidopsis. J. Exp. Bot. 56 807–816. 10.1093/jxb/eri075 PubMed DOI

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