Category: publications

Buhrow, L.M., Clark, S.M., Loewen, M.C. (2016) Identification of an attenuated barley stripe mosaic virus for the virus-induced gene silencing of pathogenesis-related wheat genes. Plant Methods 12:12. doi: 10.1186/s13007-016-0112-z.

This work represents, in part, our foray into the use of Virus Induced Genes Silencing (VIGS), for knocking down the expression of wheat genes, and testing the effect of these knockdowns on the plants resistance to wheat fungal diseases, such as Fusarium head blight (FHB).  In this instance we identified a novel variant of the VIGS expression system that imposes less ‘viral’ stress on the plant system, to enable more meaningful phenotyping of the FHB disease over the course of the experiment.

Peter C. Loewen, Allison L. Didychuk, Jacek Switala, Rosa Perez-Luque, Ignatio Fita Michele C. Loewen (2013) Structure of Pisum Sativum Rubisco with bound ribulose 1,5-bisphosphate Acta Crystallographica F 69:10-14. [PDF]

This work represents an unfunded project that has been in progress for more than a decade. We hope to follow it up shortly with something a little more intriguing, but on this same topic.

We recently deposited a new structure for Pisum sativum (a.k.a. garden pea) rubisco bound to its substrate ribulose 1,5-bisphosphate.  The structure can be accessed through the RCSB database under PDBID 4HHH.

 

Suzanne R. Abrams, Michele C. Loewen, Jason Boyd, Adrian John Cutler, Yuanzhu Gai, Kenneth, M. Nelson (2012) Inhibitors of a 9-cis epoxycarotenoid dioxygenase. United States Patent US 8,283,481 Issues Oct 9, 2012.

Our work on the development of Abscisic Acid (ABA) biosynthetic inhibitors based was finally accepted by the United States Patent Office. It was based on the rational design of a small molecule to fit and stick into the primary biosynthetic 9-cis expoxycarotenoid diogenase enzyme involved in the biosynthesis of ABA in planta.  This is related to our previous publication Boyd et al., 2009.

Characterization of the ATP Translocating Properties of the Predicted Arabidopsis thaliana Mitochondrial Adenine Nucleotice Translocator 2, Olesya, A. Kharenko & Michele C. Loewen (2010) .  Botany 88:685-690.

This work represents an output related to an ongoing project funded by the NRC Genomics and Health Initiative. It comprises development of a recombinant expression and enrichment system as well as an in vitro assay system for the detailed characterization of a plant mitochondrial ANT.

N-Terminal Residues of the Yeast Pheromone Receptor, Ste2p, Mediate Mating Events Independently of G1-Arrest Signalling. Chunhua Shi, Stephanie C. Kendall, Eric Grote, Susan Kaminskyj, Michele C. Loewen (2009) Journal of Cellular Biochemistry 107:630-638.

This work represents a collaborative effort between our laboratory at NRC and the labs of Dr. Susan Kaminskyj at the University of Saskatchewan and Dr. Eric Grote at John Hopkins. It is a continuation of the work we initiated looking at the role of the N-terminal tail of the GPCR Ste2p in mediating yeast mating events.  It comprises a systematic mutagenesis analysis of targeted residues. Please visit our Publication page to view a PDF version of the publication.

Sesquiterpene-like inhibitors of a 9-cis-epoxycarotenoid dioxygenase regulating abscisic acid biosynthesis in higher plants. Boyd, J., Gai, Y., Melson, K.M., Lukiwski, E., Talbot, J., Loewen, M.K., Owen, S., Zaharia, L.I., Cutler, A.J., Abrams, S.R., Loewen, M.C., (2009) Bioorganic and Medicinal Chemistry  17:2902-2912

This paper represents a collaborative effort between three laboratories (Loewen, Cutler and Abrams) at the Plant Biotechnology Institute.  Essentially we describe the rational design, synthesis and in vitro and in vivo testing of a series of small molecules that serve as inhibitors of the carotenoid cleavage enzyme NCED3. Chemical synthesis, protein expression and purification, enzyme kinetic analyses, hormone profiling and qPCR technologies were used to complete this project. Please visit our Publications page to view a PDF version of this paper.

In vitro characterization of ligand-induced oligomerization of the S. cerevisiae G-protein Coupled Receptor, Ste2p. Shi, C., Paige, M.F., Maley, J., Loewen, M.C. (2009) Biochimica et Biophysica Acta, 1790:1-7.

This paper represents a collaborative effort between the Loewen Lab at PBI and Dr. Matthew Paige of the Department of Chemistry at the University of Saskatchewan as well as Mr. Jason Maley of the Saskatchewan Structural Sciences Center. Essentially we demonstrate ligand induced oligomerization of Ste2p to dimeric, trimeric and possibly higher order states in detergent solubilized micelles and in isolated cell membranes. Atomic force microscopy, dynamic light scattering and chemical crosslinking methods are applied. Please visit our Publications page to view a PDF version of this paper.

Identification and characterization of a unique cysteine residue proximal to the catalytic site of Arabidopsis thaliana carotenoid cleavage enzyme 1. Guo, S., Boyd, J., Sammynaiken, R., Loewen, M.C., (2008) Biochemistry and Cell Biology 86:262-270.

This work represents a collaborative effort between the Loewen Lab and Dr. Sammynaiken of the Saskatchewan Structural Sciences Center. The work encompasses a medley of techniques ranging from UV-Vis and electron paramagnetic spectroscopies, computational modelling, site directed mutagenesis and enzymatic assays that have been applied toward the characterization of an enzyme the is involved in the modulation of plant carotenoid molecules. Please visit our Publications page to view a PDF version of this publication.