A novel phospholipase D of Arabidopsis that is activated by oleic acid and associated with the plasma membrane.
نویسندگان
چکیده
Oleate-dependent phospholipase D (PLD; EC 3.1.4.4) has been reported in animal systems, but its molecular nature is unkown. Multiple PLDs have been characterized in plants, but none of the previously cloned PLDs exhibits the oleate-activated activity. Here, we describe the biochemical and molecular identification and characterization of an oleate-activated PLD in Arabidopsis. This PLD, designated PLDdelta, was associated tightly with the plasma membrane, and its level of expression was higher in old leaves, stems, flowers, and roots than in young leaves and siliques. A cDNA encoding the oleate-activated PLD was identified, and catalytically active PLDdelta was expressed from its cDNA in Escherichia coli. PLDdelta was activated by free oleic acid in a dose-dependent manner, with the optimal concentration being 0.5 mM. Other unsaturated fatty acids, linoleic and linolenic acids, were less effective than oleic acid, whereas the saturated fatty acids, stearic and palmitic acids, were totally ineffective. Phosphatidylinositol 4,5-bisphosphate stimulated PLDdelta to a lesser extent than oleate. Mutation at arginine (Arg)-611 led to a differential loss of the phosphatidylinositol 4,5-bisphosphate-stimulated activity of PLDdelta, indicating that separate sites mediate the oleate regulation of PLDdelta. Oleate stimulated PLDdelta's binding to phosphatidylcholine. Mutation at Arg-399 resulted in a decrease in oleate binding by PLDdelta and a loss of PLDdelta activity. However, this mutation bound similar levels of phosphatidylcholine as wild type, suggesting that Arg-399 is not required for PC binding. These results provide the molecular information on oleate-activated PLD and also suggest a mechanism for the oleate stimulation of this enzyme.
منابع مشابه
Arabidopsis leaf plasma membrane proteome using a gel free method: Focus on receptor–like kinases
The hydrophobic proteins of plant plasma membrane still remain largely unknown. For example in the Arabidopsis genome, receptor-like kinases (RLKs) are plasma membrane proteins, functioning as the primary receptors in the signaling of stress conditions, hormones and the presence of pathogens form a diverse family of over 610 genes. A limited number of these proteins have appeard in pr...
متن کاملModification of activated carbon by cold plasma and its effect on the adsorption of toluene
Abstract Background and aims: Clean air is one of the basic needs for human health and well-being. However, along with economic growth and development, transportation, urbanization and energy consumption have also risen and provide many concerns such as air pollution, which require urgent and wide attention. Air pollution in the worldwide is considered as a risk factor for human health and one...
متن کاملیافته های تازه درباره سلولهای پاریتال معده
During the last five years the recognition of ionic channels in the parietal cells of stomach and acid chloride mechanisms of secretion by these cells has become totally clear by the "Patch Oamp" technique. The apical cytoplasm in the oxyntic cells are in the form of vesicles where membranes contain H+, K+ -ATPase pump. Stimulation causes fusion of these tubular vesicles with the cell membran o...
متن کاملPreparation and Characterization of a Novel Biodegradable Epoxy Resin Modified with Epoxidized Oleic Acid
The goal of this research was to study the curing behavior and biodegradability DER 736 modified with epoxidized oleic acid. In this paper we demonstrate the efficient epoxidation of oleic acid with performic acid generated in situ from formic acid and hydrogen peroxide in the presence of H2SO4 as catalyst. The highest relative epoxy yield of 61% was achieved at 40 ͦC after 10 h. DER 736 modifie...
متن کاملEffects of Ramadan fasting on plasma free fatty acids in patients with non-alcoholic fatty liver disease
Introduction: Nonalcoholic fatty liver disease (NAFLD) is a global disease which its prevalence is about 10-35%. Several factors are involved in the pathogenesis of the disease. The present study was conducted to evaluate the effect of fasting during Ramadan on plasma free fatty acids in patients with NAFLD.Methods: This cross-sectional study was performed during the month of Ramadan in June-Ju...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Plant physiology
دوره 127 3 شماره
صفحات -
تاریخ انتشار 2001