--- _id: '826' abstract: - lang: eng text: Plants exhibit a unique developmental flexibility to ever-changing environmental conditions. To achieve their profound adaptability, plants are able to maintain permanent stem cell populations and form new organs during the entire plant life cycle. Signaling substances, called plant hormones, such as auxin, cytokinin, abscisic acid, brassinosteroid, ethylene, gibberellin, jasmonic acid, and strigolactone, govern and coordinate these developmental processes. Physiological and genetic studies have dissected the molecular components of signal perception and transduction of the individual hormonal pathways. However, over recent years it has become evident that hormones do not act only in a linear pathway. Hormonal pathways are interconnected by a complex network of interactions and feedback circuits that determines the final outcome of the individual hormone actions. This raises questions about the molecular mechanisms underlying hormonal cross talk and about how these hormonal networks are established, maintained, and modulated throughout plant development. acknowledgement: We would like to thank Annick Bleys for help in preparing the manuscript. This work was supported by the European Research Council with a Starting Independent Research grant (ERC-2007-Stg-207362-HCPO) and the project CZ.1.07/2.3.00/20.0043 (to the Central European Institute of Technology, CEITEC) to E.B. M.V. is a postdoctoral fellow of the Research Foundation Flanders. We apologize that, because of space restrictions, the scientific contributions of only a limited number of original articles could be cited and discussed. author: - first_name: Marleen full_name: Vanstraelen, Marleen last_name: Vanstraelen - first_name: Eva full_name: Eva Benková id: 38F4F166-F248-11E8-B48F-1D18A9856A87 last_name: Benková orcid: 0000-0002-8510-9739 citation: ama: Vanstraelen M, Benková E. Hormonal interactions in the regulation of plant development. Annual Review of Cell and Developmental Biology. 2012;28:463-487. doi:10.1146/annurev-cellbio-101011-155741 apa: Vanstraelen, M., & Benková, E. (2012). Hormonal interactions in the regulation of plant development. Annual Review of Cell and Developmental Biology. Annual Reviews. https://doi.org/10.1146/annurev-cellbio-101011-155741 chicago: Vanstraelen, Marleen, and Eva Benková. “Hormonal Interactions in the Regulation of Plant Development.” Annual Review of Cell and Developmental Biology. Annual Reviews, 2012. https://doi.org/10.1146/annurev-cellbio-101011-155741. ieee: M. Vanstraelen and E. Benková, “Hormonal interactions in the regulation of plant development,” Annual Review of Cell and Developmental Biology, vol. 28. Annual Reviews, pp. 463–487, 2012. ista: Vanstraelen M, Benková E. 2012. Hormonal interactions in the regulation of plant development. Annual Review of Cell and Developmental Biology. 28, 463–487. mla: Vanstraelen, Marleen, and Eva Benková. “Hormonal Interactions in the Regulation of Plant Development.” Annual Review of Cell and Developmental Biology, vol. 28, Annual Reviews, 2012, pp. 463–87, doi:10.1146/annurev-cellbio-101011-155741. short: M. Vanstraelen, E. Benková, Annual Review of Cell and Developmental Biology 28 (2012) 463–487. date_created: 2018-12-11T11:48:43Z date_published: 2012-11-01T00:00:00Z date_updated: 2021-01-12T08:17:46Z day: '01' doi: 10.1146/annurev-cellbio-101011-155741 extern: 1 intvolume: ' 28' month: '11' page: 463 - 487 publication: Annual Review of Cell and Developmental Biology publication_status: published publisher: Annual Reviews publist_id: '6822' quality_controlled: 0 status: public title: Hormonal interactions in the regulation of plant development type: journal_article volume: 28 year: '2012' ... --- _id: '829' abstract: - lang: eng text: The architecture of a plant's root system, established postembryonically, results from both coordinated root growth and lateral root branching. The plant hormones auxin and cytokinin are central endogenous signaling molecules that regulate lateral root organogenesis positively and negatively, respectively. Tight control and mutual balance of their antagonistic activities are particularly important during the early phases of lateral root organogenesis to ensure continuous lateral root initiation (LRI) and proper development of lateral root primordia (LRP). Here, we show that the early phases of lateral root organogenesis, including priming and initiation, take place in root zones with a repressed cytokinin response. Accordingly, ectopic overproduction of cytokinin in the root basal meristem most efficiently inhibits LRI. Enhanced cytokinin responses in pericycle cells between existing LRP might restrict LRI near existing LRP and, when compromised, ectopic LRI occurs. Furthermore, our results demonstrate that young LRP are more sensitive to perturbations in the cytokinin activity than are developmentally more advanced primordia. We hypothesize that the effect of cytokinin on the development of primordia possibly depends on the robustness and stability of the auxin gradient. acknowledgement: We thank Jen Sheen, Dolf Weijers, Tatsuo Kakimoto, Stephen Depuydt, and Laurent Laplaze for sharing published material, Jiri Friml for discussions, and Martine De Cock and Annick Bleys for help in preparing the manuscript. This work was supported by a Starting Independent Research grant from the European Research Council (ERC-2007-Stg-207362-HCPO) and the project CZ.1.07/2.3.00/20.0043 to the Central European Institute of Technology to E.B. and grants from the Ministry of Education, Youth, and Sports of the Czech Republic (MSM 6198959216) and the Centre of the Region Haná for Biotechnological and Agricultural Research (ED0007/01/01) to P.T. author: - first_name: Agnieszka full_name: Bielach, Agnieszka last_name: Bielach - first_name: Katerina full_name: Podlesakova, Katerina last_name: Podlesakova - first_name: Peter full_name: Peter Marhavy id: 3F45B078-F248-11E8-B48F-1D18A9856A87 last_name: Marhavy orcid: 0000-0001-5227-5741 - first_name: Jérôme full_name: Duclercq, Jérôme last_name: Duclercq - first_name: Candela full_name: Candela Cuesta id: 33A3C818-F248-11E8-B48F-1D18A9856A87 last_name: Cuesta orcid: 0000-0003-1923-2410 - first_name: Bruno full_name: Muller, Bruno last_name: Muller - first_name: Wim full_name: Grunewald, Wim last_name: Grunewald - first_name: Petr full_name: Tarkowski, Petr last_name: Tarkowski - first_name: Eva full_name: Eva Benková id: 38F4F166-F248-11E8-B48F-1D18A9856A87 last_name: Benková orcid: 0000-0002-8510-9739 citation: ama: Bielach A, Podlesakova K, Marhavý P, et al. Spatiotemporal regulation of lateral root organogenesis in Arabidopsis by cytokinin. The Plant Cell. 2012;24(10):3967-3981. doi:10.1105/tpc.112.103044 apa: Bielach, A., Podlesakova, K., Marhavý, P., Duclercq, J., Cuesta, C., Muller, B., … Benková, E. (2012). Spatiotemporal regulation of lateral root organogenesis in Arabidopsis by cytokinin. The Plant Cell. American Society of Plant Biologists. https://doi.org/10.1105/tpc.112.103044 chicago: Bielach, Agnieszka, Katerina Podlesakova, Peter Marhavý, Jérôme Duclercq, Candela Cuesta, Bruno Muller, Wim Grunewald, Petr Tarkowski, and Eva Benková. “Spatiotemporal Regulation of Lateral Root Organogenesis in Arabidopsis by Cytokinin.” The Plant Cell. American Society of Plant Biologists, 2012. https://doi.org/10.1105/tpc.112.103044. ieee: A. Bielach et al., “Spatiotemporal regulation of lateral root organogenesis in Arabidopsis by cytokinin,” The Plant Cell, vol. 24, no. 10. American Society of Plant Biologists, pp. 3967–3981, 2012. ista: Bielach A, Podlesakova K, Marhavý P, Duclercq J, Cuesta C, Muller B, Grunewald W, Tarkowski P, Benková E. 2012. Spatiotemporal regulation of lateral root organogenesis in Arabidopsis by cytokinin. The Plant Cell. 24(10), 3967–3981. mla: Bielach, Agnieszka, et al. “Spatiotemporal Regulation of Lateral Root Organogenesis in Arabidopsis by Cytokinin.” The Plant Cell, vol. 24, no. 10, American Society of Plant Biologists, 2012, pp. 3967–81, doi:10.1105/tpc.112.103044. short: A. Bielach, K. Podlesakova, P. Marhavý, J. Duclercq, C. Cuesta, B. Muller, W. Grunewald, P. Tarkowski, E. Benková, The Plant Cell 24 (2012) 3967–3981. date_created: 2018-12-11T11:48:43Z date_published: 2012-10-01T00:00:00Z date_updated: 2021-01-12T08:17:55Z day: '01' doi: 10.1105/tpc.112.103044 extern: 1 intvolume: ' 24' issue: '10' month: '10' page: 3967 - 3981 publication: The Plant Cell publication_status: published publisher: American Society of Plant Biologists publist_id: '6819' quality_controlled: 0 status: public title: Spatiotemporal regulation of lateral root organogenesis in Arabidopsis by cytokinin type: journal_article volume: 24 year: '2012' ... --- _id: '846' abstract: - lang: eng text: Whether or not evolutionary change is inherently irreversible remains a controversial topic. Some examples of evolutionary irreversibility are known; however, this question has not been comprehensively addressed at the molecular level. Here, we use data from 221 human genes with known pathogenic mutations to estimate the rate of irreversibility in protein evolution. For these genes, we reconstruct ancestral amino acid sequences along the mammalian phylogeny and identify ancestral amino acid states that match known pathogenic mutations. Such cases represent inherent evolutionary irreversibility because, at the present moment, reversals to these ancestral amino acid states are impossible for the human lineage. We estimate that approximately 10% of all amino acid substitutions along the mammalian phylogeny are irreversible, such that a return to the ancestral amino acid state would lead to a pathogenic phenotype. For a subset of 51 genes with high rates of irreversibility, as much as 40% of all amino acid evolution was estimated to be irreversible. Because pathogenic phenotypes do not resemble ancestral phenotypes, the molecular nature of the high rate of irreversibility in proteins is best explained by evolution with a high prevalence of compensatory, epistatic interactions between amino acid sites. Under such mode of protein evolution, once an amino acid substitution is fixed, the probability of its reversal declines as the protein sequence accumulates changes that affect the phenotypic manifestation of the ancestral state. The prevalence of epistasis in evolution indicates that the observed high rate of irreversibility in protein evolution is an inherent property of protein structure and function. acknowledgement: This work was supported by Plan Nacional grant BFU2009-09271 from the Spanish Ministry of Science and Innovation and by FPU (Formación del Profesorado Universitario) program grant AP2008-01888 from the Spanish Ministry of Education to O.S. F.A.K. is a European Molecular Biology Organization Young Investigator and Howard Hughes Medical Institute International Early Career Scientist. author: - first_name: Onuralp full_name: Soylemez, Onuralp last_name: Soylemez - first_name: Fyodor full_name: Fyodor Kondrashov id: 44FDEF62-F248-11E8-B48F-1D18A9856A87 last_name: Kondrashov orcid: 0000-0001-8243-4694 citation: ama: Soylemez O, Kondrashov F. Estimating the rate of irreversibility in protein evolution. Genome Biology and Evolution. 2012;4(12):1213-1222. doi:10.1093/gbe/evs096 apa: Soylemez, O., & Kondrashov, F. (2012). Estimating the rate of irreversibility in protein evolution. Genome Biology and Evolution. Oxford University Press. https://doi.org/10.1093/gbe/evs096 chicago: Soylemez, Onuralp, and Fyodor Kondrashov. “Estimating the Rate of Irreversibility in Protein Evolution.” Genome Biology and Evolution. Oxford University Press, 2012. https://doi.org/10.1093/gbe/evs096. ieee: O. Soylemez and F. Kondrashov, “Estimating the rate of irreversibility in protein evolution,” Genome Biology and Evolution, vol. 4, no. 12. Oxford University Press, pp. 1213–1222, 2012. ista: Soylemez O, Kondrashov F. 2012. Estimating the rate of irreversibility in protein evolution. Genome Biology and Evolution. 4(12), 1213–1222. mla: Soylemez, Onuralp, and Fyodor Kondrashov. “Estimating the Rate of Irreversibility in Protein Evolution.” Genome Biology and Evolution, vol. 4, no. 12, Oxford University Press, 2012, pp. 1213–22, doi:10.1093/gbe/evs096. short: O. Soylemez, F. Kondrashov, Genome Biology and Evolution 4 (2012) 1213–1222. date_created: 2018-12-11T11:48:49Z date_published: 2012-01-01T00:00:00Z date_updated: 2021-01-12T08:19:25Z day: '01' doi: 10.1093/gbe/evs096 extern: 1 intvolume: ' 4' issue: '12' license: https://creativecommons.org/licenses/by-nc/4.0/ month: '01' page: 1213 - 1222 publication: Genome Biology and Evolution publication_status: published publisher: Oxford University Press publist_id: '6802' quality_controlled: 0 status: public title: Estimating the rate of irreversibility in protein evolution tmp: image: /images/cc_by_nc.png legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) short: CC BY-NC (4.0) type: journal_article volume: 4 year: '2012' ... --- _id: '8463' abstract: - lang: eng text: The 1H dipolar network, which is the major obstacle for applying proton detection in the solid-state, can be reduced by deuteration, employing the RAP (Reduced Adjoining Protonation) labeling scheme, which yields random protonation at non-exchangeable sites. We present here a systematic study on the optimal degree of random sidechain protonation in RAP samples as a function of the MAS (magic angle spinning) frequency. In particular, we compare 1H sensitivity and linewidth of a microcrystalline protein, the SH3 domain of chicken α-spectrin, for samples, prepared with 5–25 % H2O in the E. coli growth medium, in the MAS frequency range of 20–60 kHz. At an external field of 19.96 T (850 MHz), we find that using a proton concentration between 15 and 25 % in the M9 medium yields the best compromise in terms of sensitivity and resolution, with an achievable average 1H linewidth on the order of 40–50 Hz. Comparing sensitivities at a MAS frequency of 60 versus 20 kHz, a gain in sensitivity by a factor of 4–4.5 is observed in INEPT-based 1H detected 1D 1H,13C correlation experiments. In total, we find that spectra recorded with a 1.3 mm rotor at 60 kHz have almost the same sensitivity as spectra recorded with a fully packed 3.2 mm rotor at 20 kHz, even though ~20× less material is employed. The improved sensitivity is attributed to 1H line narrowing due to fast MAS and to the increased efficiency of the 1.3 mm coil. article_processing_charge: No article_type: original author: - first_name: Sam full_name: Asami, Sam last_name: Asami - first_name: Kathrin full_name: Szekely, Kathrin last_name: Szekely - first_name: Paul full_name: Schanda, Paul id: 7B541462-FAF6-11E9-A490-E8DFE5697425 last_name: Schanda orcid: 0000-0002-9350-7606 - first_name: Beat H. full_name: Meier, Beat H. last_name: Meier - first_name: Bernd full_name: Reif, Bernd last_name: Reif citation: ama: Asami S, Szekely K, Schanda P, Meier BH, Reif B. Optimal degree of protonation for 1H detection of aliphatic sites in randomly deuterated proteins as a function of the MAS frequency. Journal of Biomolecular NMR. 2012;54(2):155-168. doi:10.1007/s10858-012-9659-9 apa: Asami, S., Szekely, K., Schanda, P., Meier, B. H., & Reif, B. (2012). Optimal degree of protonation for 1H detection of aliphatic sites in randomly deuterated proteins as a function of the MAS frequency. Journal of Biomolecular NMR. Springer Nature. https://doi.org/10.1007/s10858-012-9659-9 chicago: Asami, Sam, Kathrin Szekely, Paul Schanda, Beat H. Meier, and Bernd Reif. “Optimal Degree of Protonation for 1H Detection of Aliphatic Sites in Randomly Deuterated Proteins as a Function of the MAS Frequency.” Journal of Biomolecular NMR. Springer Nature, 2012. https://doi.org/10.1007/s10858-012-9659-9. ieee: S. Asami, K. Szekely, P. Schanda, B. H. Meier, and B. Reif, “Optimal degree of protonation for 1H detection of aliphatic sites in randomly deuterated proteins as a function of the MAS frequency,” Journal of Biomolecular NMR, vol. 54, no. 2. Springer Nature, pp. 155–168, 2012. ista: Asami S, Szekely K, Schanda P, Meier BH, Reif B. 2012. Optimal degree of protonation for 1H detection of aliphatic sites in randomly deuterated proteins as a function of the MAS frequency. Journal of Biomolecular NMR. 54(2), 155–168. mla: Asami, Sam, et al. “Optimal Degree of Protonation for 1H Detection of Aliphatic Sites in Randomly Deuterated Proteins as a Function of the MAS Frequency.” Journal of Biomolecular NMR, vol. 54, no. 2, Springer Nature, 2012, pp. 155–68, doi:10.1007/s10858-012-9659-9. short: S. Asami, K. Szekely, P. Schanda, B.H. Meier, B. Reif, Journal of Biomolecular NMR 54 (2012) 155–168. date_created: 2020-09-18T10:09:18Z date_published: 2012-08-23T00:00:00Z date_updated: 2021-01-12T08:19:27Z day: '23' doi: 10.1007/s10858-012-9659-9 extern: '1' intvolume: ' 54' issue: '2' language: - iso: eng month: '08' oa_version: None page: 155-168 publication: Journal of Biomolecular NMR publication_identifier: issn: - 0925-2738 - 1573-5001 publication_status: published publisher: Springer Nature quality_controlled: '1' status: public title: Optimal degree of protonation for 1H detection of aliphatic sites in randomly deuterated proteins as a function of the MAS frequency type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 54 year: '2012' ... --- _id: '8465' abstract: - lang: eng text: We demonstrate that conformational exchange processes in proteins on microsecond-to-millisecond time scales can be detected and quantified by solid-state NMR spectroscopy. We show two independent approaches that measure the effect of conformational exchange on transverse relaxation parameters, namely Carr–Purcell–Meiboom–Gill relaxation-dispersion experiments and measurement of differential multiple-quantum coherence decay. Long coherence lifetimes, as required for these experiments, are achieved by the use of highly deuterated samples and fast magic-angle spinning. The usefulness of the approaches is demonstrated by application to microcrystalline ubiquitin. We detect a conformational exchange process in a region of the protein for which dynamics have also been observed in solution. Interestingly, quantitative analysis of the data reveals that the exchange process is more than 1 order of magnitude slower than in solution, and this points to the impact of the crystalline environment on free energy barriers. article_processing_charge: No article_type: original author: - first_name: Martin full_name: Tollinger, Martin last_name: Tollinger - first_name: Astrid C. full_name: Sivertsen, Astrid C. last_name: Sivertsen - first_name: Beat H. full_name: Meier, Beat H. last_name: Meier - first_name: Matthias full_name: Ernst, Matthias last_name: Ernst - first_name: Paul full_name: Schanda, Paul id: 7B541462-FAF6-11E9-A490-E8DFE5697425 last_name: Schanda orcid: 0000-0002-9350-7606 citation: ama: Tollinger M, Sivertsen AC, Meier BH, Ernst M, Schanda P. Site-resolved measurement of microsecond-to-millisecond conformational-exchange processes in proteins by solid-state NMR spectroscopy. Journal of the American Chemical Society. 2012;134(36):14800-14807. doi:10.1021/ja303591y apa: Tollinger, M., Sivertsen, A. C., Meier, B. H., Ernst, M., & Schanda, P. (2012). Site-resolved measurement of microsecond-to-millisecond conformational-exchange processes in proteins by solid-state NMR spectroscopy. Journal of the American Chemical Society. American Chemical Society. https://doi.org/10.1021/ja303591y chicago: Tollinger, Martin, Astrid C. Sivertsen, Beat H. Meier, Matthias Ernst, and Paul Schanda. “Site-Resolved Measurement of Microsecond-to-Millisecond Conformational-Exchange Processes in Proteins by Solid-State NMR Spectroscopy.” Journal of the American Chemical Society. American Chemical Society, 2012. https://doi.org/10.1021/ja303591y. ieee: M. Tollinger, A. C. Sivertsen, B. H. Meier, M. Ernst, and P. Schanda, “Site-resolved measurement of microsecond-to-millisecond conformational-exchange processes in proteins by solid-state NMR spectroscopy,” Journal of the American Chemical Society, vol. 134, no. 36. American Chemical Society, pp. 14800–14807, 2012. ista: Tollinger M, Sivertsen AC, Meier BH, Ernst M, Schanda P. 2012. Site-resolved measurement of microsecond-to-millisecond conformational-exchange processes in proteins by solid-state NMR spectroscopy. Journal of the American Chemical Society. 134(36), 14800–14807. mla: Tollinger, Martin, et al. “Site-Resolved Measurement of Microsecond-to-Millisecond Conformational-Exchange Processes in Proteins by Solid-State NMR Spectroscopy.” Journal of the American Chemical Society, vol. 134, no. 36, American Chemical Society, 2012, pp. 14800–07, doi:10.1021/ja303591y. short: M. Tollinger, A.C. Sivertsen, B.H. Meier, M. Ernst, P. Schanda, Journal of the American Chemical Society 134 (2012) 14800–14807. date_created: 2020-09-18T10:10:20Z date_published: 2012-08-21T00:00:00Z date_updated: 2021-01-12T08:19:27Z day: '21' doi: 10.1021/ja303591y extern: '1' intvolume: ' 134' issue: '36' language: - iso: eng month: '08' oa_version: None page: 14800-14807 publication: Journal of the American Chemical Society publication_identifier: issn: - 0002-7863 - 1520-5126 publication_status: published publisher: American Chemical Society quality_controlled: '1' status: public title: Site-resolved measurement of microsecond-to-millisecond conformational-exchange processes in proteins by solid-state NMR spectroscopy type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 134 year: '2012' ...