The γ-tocopherol-like family of N-methyltransferases: A taxonomically clustered gene family encoding enzymes responsible for N-methylation of monoterpene indole alkaloids

The plant family Apocynaceae accumulates thousands of monoterpene indole alkaloids (MIAs) which originate, biosynthetically, from the common secoiridoid intermediate, strictosidine, that is formed from the condensation of tryptophan and secologanin molecules. MIAs demonstrate remarkable structural diversity and have pharmaceutically valuable biological activities. For example; a subunit of the potent anti-neoplastic molecules vincristine and vinblastine is the aspidosperma alkaloid, vindoline. Vindoline accumulates to trace levels under natural conditions. Research programs have determined that there is significant developmental and light regulation involved in the biosynthesis of this MIA. Furthermore, the biosynthetic pathway leading to vindoline is split among at least five independent cell types. Little is known of how intermediates are shuttled between these cell types. The late stage events in vindoline biosynthesis involve six enzymatic steps from tabersonine. The fourth biochemical step, in this pathway, is an indole N-methylation performed by a recently identified N-methyltransfearse (NMT). For almost twenty years the gene encoding this NMT had eluded discovery; however, in 2010 Liscombe et al. reported the identification of a γ-tocopherol C-methyltransferase homologue capable of indole N-methylating 2,3-dihydrotabersonine and Virus Induced Gene Silencing (VIGS) suppression of the messenger has since proven its involvement in vindoline biosynthesis. Recent large scale sequencing initiatives, performed on non-model medicinal plant transcriptomes, has permitted identification of candidate genes, presumably involved, in MIA biosynthesis never seen before in plant specialized metabolism research. Probing the transcriptome assemblies of Catharanthus roseus (L.)G.Don, Vinca minor L., Rauwolfia serpentine (L.)Benth ex Kurz, Tabernaemontana elegans, and Amsonia hubrichtii, with the nucleotide sequence of the N-methyltransferase involved in vindoline biosynthesis, revealed eight new homologous methyltransferases. This thesis describes the identification, molecular cloning, recombinant expression and biochemical characterization of two picrinine NMTs, one from V. minor and one from R. serpentina, a perivine NMT from C. roseus, and an ajmaline NMT from R. serpentina. While these TLMTs were expressed and functional in planta, they were active at relatively low levels and their N-methylated alkaloid products were not apparent our from alkaloid isolates of the plants. It appears that, for the most part, these TLMTs, participate in apparently silent biochemical pathways, awaiting the appropriate developmental and environmental cues for activity.

alpha-Tocopherol's Antioxidant Role: A Biophysical Perspective

I present evidence of an antioxidant mechanism for vitamin E that correlates strongly with its physical location in a model lipid bilayer. These data address the overlooked problem of the physical distance between the vitamin's reducing hydrogen and lipid acyl chain radicals. The combined data from neutron diffraction, NMR and UV spectroscopy experiments, all suggest that reduction of reactive oxygen species and lipid radicals occurs specifically at the membrane's hydrophobic-hydrophilic interface. The latter is possible when the acyl chain adopts conformations in which they snorkel to the interface from the hydrocarbon matrix. Moreover, not all model lipids are equal in this regard, as indicated by the small differences in the vitamin's location. The present result is a clear example of the importance of lipid diversity in controlling the dynamic structural properties of biological membranes. Importantly, these results suggest that measurements of alpha-tocopherol oxidation kinetics, and its products, should be revisited by taking into consideration the physical properties of the membrane in which the vitamin resides.

Polyunsaturated Fatty Acids (PUFA) Regulate Neurotransmitter Contents in Rat Brain

The effects of feeding of 6-propyllhiouracil (6-I'fU) and potyunsaturatcd fatty acids (I'UFA) independently and ill combination and administration (ip) of a single close of Iriiodothyronine (I',) (2.51ig/IOOg body wl) along with feeding of 6- PTU and PUFA were studied in cal brain. Dopamine (DA), 5-hydroxytryplophan (5-IIl'I'), serolouin (5-Ill), 5-hydioxy indole acetic acid (5-111AA), norepinephrine (NF) :uul ceinephrinn (I?I'l) contenls were assayed in the hypothalannls and ccrc bral cortex regions. It was found that 6-P"l'U Iccding resulted in decrease in dopamine, 5-III', 5 II I I' and 5 IIiAA in both regions. In animals fed wills PUFA followed by adnliuislralion of T,. the I)A level was found normal.

Guia per a l'adaptació a l'espai europeu d'educació superior: 6. Continguts = Guía para la adaptación al espacio europeo de educación superior: 6. Contenidos = Guide to Adaptation to the European Higher Education Area: 6. Contents

Aquest quadern és el sisè lliurament de la Guia per a l'adaptació a l'espai europeu d'educació superior. Té l'origen en el debat de la Comissió de Seguiment del Pla Pilot d'Adaptació a l'Espai Europeu d'Educació Superior de la UdG i del grup de treball que s'ha constituït expressament per tractar el tema de l'avaluació dels aprenentatges

Analysis and regeneration of hypermedia contents through Java and XML tools

This paper presents a tool for the analysis and regeneration of Web contents, implemented through XML and Java. At the moment, the Web content delivery from server to clients is carried out without taking into account clients' characteristics. Heterogeneous and diverse characteristics, such as user's preferences, different capacities of the client's devices, different types of access, state of the network and current load on the server, directly affect the behavior of Web services. On the other hand, the growing use of multimedia objects in the design of Web contents is made without taking into account this diversity and heterogeneity. It affects, even more, the appropriate content delivery. Thus, the objective of the presented tool is the treatment of Web pages taking into account the mentioned heterogeneity and adapting contents in order to improve the performance on the Web

Using Tables of Contents in MS Word 2010

A Table of Contents can be automatically generated and refreshed in a Word document so long as you use Heading styles (see the Heading Styles video). This video shows how to use Tables of Contents in the University’s Thesis Template. For best viewing Download the video.

How to make a Table of Contents to cover only part of the file in MS Word 2010

A Table of Contents can be tweaked so that it picks up the content from only part of a file (such as an Appendix). This video shows you how to make such a change to a Table of Contents that is based upon Heading Styles. For best viewing Download the video.

Using the TitlePage, Contents and Appendix styles in the University's thesis template for MS Word 2010

This video shows you when and how to use the styles TitlePage, Contents and Appendix styles in the University's thesis template in Word 2010. For best viewing Download the video.

Using Tables of Contents in MS Word 2011

A Table of Contents can be automatically generated and refreshed in a Word document so long as you use Heading styles (see the Heading Styles video). This video shows how to use Tables of Contents in the University’s thesis template. For best viewing Download the video.

Creating a Table of Contents to cover only part of a file's content using MS Word 2011 for Apple computers

A Table of Contents can be tweaked so that it picks up the content from only part of a file (such as an Appendix). This video shows you how to make such a change to a Table of Contents that is based upon Heading Styles. For best viewing Download the video.

Using the Contents and Appendix styles in the University's thesis template for MS Word 2011

This video shows you when and how to use the styles Contents and Appendix styles in the University's thesis template in Word 2011. For best viewing Download the video.

E.T.C. -English Through Contents- programa de aprendizaje de lengua a trav??s de contenidos

El art??culo forma parte de un monogr??fico de la revista dedicado a las lenguas extranjeras

ETC : English Through Contents.

Resumen tomado de la web del Departamento de Educación