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Showing papers by "John L. Harwood published in 2014"


Journal ArticleDOI
TL;DR: The classic heat shock (stress) response (HSR) was originally attributed to protein denaturation, but it is observed that a deregulated HSR is found in a large number of important diseases where more detailed knowledge of the molecular mechanisms involved may offer timely opportunities for clinical interventions and new, innovative drug treatments.

120 citations


Journal ArticleDOI
TL;DR: The important role for cholinephosphate cytidylyltransferase in the biosynthesis of the major extra-plastidic membrane lipid, phosphatidylcholine is demonstrated and control analysis to light-induced fatty acid synthesis was applied, the first such application to lipid synthesis in any organism.

51 citations


Journal ArticleDOI
TL;DR: In this paper, the molecular and biochemical bases for the accumulation of stearic acid in sunflower seeds are discussed, and the aspects limiting the stearate in the seeds of this species are reviewed.

24 citations


Journal ArticleDOI
25 Mar 2014-PLOS ONE
TL;DR: It is concluded that properdin plays an unexpectedly beneficial role in the development and progression of early atherosclerotic lesions.
Abstract: Genetic, dietary and immune factors contribute to the pathogenesis of atherosclerosis in humans and mice. Complement activation is an integral part of the innate immune defence but also shapes cellular responses and influences directly triglyceride synthesis. Deficiency of Factor B of the alternative pathway (AP) of complement is beneficial in LDLR−/− mice fed a high fat diet. The serum glycoprotein properdin is a key positive regulator of the AP but has not been studied in experimental atherosclerosis. Atherosclerosis was assessed after feeding low fat (LFD) or high fat (HFD) Western type diets to newly generated LDLR−/− ProperdinKO (LDLR−/−PKO) and LDLR−/−PWT mice. Lipids, lymphocytes and monocytes were similar among genotypes, genders and diets. Complement C3, but not C3adesarg, levels were enhanced in LDLR−/−PKO mice regardless of diet type or gender. Non-esterified fatty acids (NEFA) were decreased in male LDLR−/−PKO fed a HFD compared with controls. All mice showed significant atherosclerotic burden in aortae and at aortic roots but male LDLR−/− mice fed a LFD were affected to the greatest extent by the absence of properdin. The protective effect of properdin expression was overwhelmed in both genders of LDLR−/−mice when fed a HFD. We conclude that properdin plays an unexpectedly beneficial role in the development and progression of early atherosclerotic lesions.

22 citations


Journal ArticleDOI
TL;DR: RNA editing is proposed as a novel molecular process underpinning VHA trafficking and intracellular sequestration of heavy metals under stress by exploiting laboratory exposures and samples from an environmental copper gradient to show that total VHA-A transcript and protein were induced by copper.
Abstract: A V-ATPase subunit A protein (VHA-A) transcript together with a variant (C793 to U), which introduces a stop codon truncating the subunit immediately downstream of its ATP binding site, was identified within a Fucus vesiculosus cDNA from a heavy metal contaminated site. This is intriguing because the VHA-A subunit is the crucial catalytic subunit responsible for the hydrolysis of ATP that drives ion transport underlying heavy metal detoxification pathways. We employed a chemiluminescent hybridization protection assay to quantify the proportion of both variants directly from mRNA while performing quantification of total transcript using Q-PCR. Polyclonal antisera raised against recombinant VHA-A facilitated simultaneous detection of parent and truncated VHA-A and revealed its cellular and subcellular localization. By exploiting laboratory exposures and samples from an environmental copper gradient, we showed that total VHA-A transcript and protein, together with levels of the truncated variant, were induced by copper. The absence of a genomic sequence representing the truncated variant suggests a RNA editing event causing the production of the truncated VHA-A. Based on these observations, we propose RNA editing as a novel molecular process underpinning VHA trafficking and intracellular sequestration of heavy metals under stress.

8 citations


Journal ArticleDOI
TL;DR: This review describes experiments using metabolic control analysis on important crops – oil palm, oilseed rape, olive and soybean to provide information for future informed genetic manipulations.
Abstract: Oil crops are a very important agricultural commodity. Demand for such oils is rising steadily (at more than 5% per year over the last half century). Although the majority of plant oils are used for food or animal feed, there is increasing interest in their use as renewable chemicals for industry. Because of the demonstrated demand for oils and finite agricultural land, attention is focussing on improving productivity. Genetic manipulation of crop plants needs a knowledge of the biosynthetic pathways concerned and how they are regulated. Although there are different ways to acquire much information, metabolic flux and metabolic control analyses are ways to provide quantitative assessments. In this review we describe our experiments using metabolic control analysis on important crops – oil palm, oilseed rape, olive and soybean. Such research provides information for future informed genetic manipulations and we give a successful example of this in oilseed rape (Brassica napus L.).

8 citations


Journal ArticleDOI
TL;DR: The great French scientist Chevreul made contributions to several different areas of science so, in humble appreciation of his seminal discoveries, he will discuss some diverse lipid topics that he has worked on.
Abstract: As an undergraduate student of Medical Biochemistry, I was unsure what I wanted to do with my life after graduating. Then, one day, I had a lecture about membrane lipids. It turned out that not only were they far from the inert structural compounds that they were often portrayed to be but they turned over quite rapidly. But there was one class of lipids—the higher inositides (PtdIns4P, PtdIns (4, 5) P2)—that had a T½ of only a few minutes! I found this fascinating and was inspired not only to do my post-graduate work with J. N. (Tim) Hawthorne on inositides but to continue work on lipids ever since. I have no regrets for it has been a fascinating journey. The great French scientist Chevreul made contributions to several different areas of science so, in humble appreciation of his seminal discoveries, I will discuss some diverse lipid topics that I have worked on.

2 citations


Reference EntryDOI
23 Jun 2014
TL;DR: This chapter describes the most useful methods currently in use including the use of isotopes to study metabolism, as well as prospects for useful future developments.
Abstract: Lipids are vital constituents of cells – as membrane components, energy stores, signaling molecules, and surface compounds. In this article, we describe major lipids, how they can be extracted, and precautions in their handling. Specific methods for lipid analysis including radioisotope work, thin‐layer and gas–liquid chromatography and mass spectroscopy are then described and discussed.

1 citations