Novel Polyunsaturated N-acylethanolamines (NAE) and Their Role in Physcomitrella Patens
Anandamide (N-arachidonoylethanolamide, AEA), a 20C polyunsaturated (PU) N-acylethanolamine (NAE) influences many neurological functions in mammals. Although 20C PU-NAEs are considered unique to animals, they were recently discovered in early land plants but their metabolism and functions remain unknown. Comprehensive lipidomic analyses of Physcomitrella patens revealed not only abundance of arachidonic acid (AA, 20:4) and eicosapentaenoic acid (EPA, 20:5) but also their corresponding ethanolamides (AEA and EPEA, respectively). While moss showed increasing AA with development, 14% and 24% in protonemata and gametophyte tissues, respectively, EPA decreased from 7% in protonemata to ~1.3 % in gametophytes. An increase in 20:4- and decrease in 20:5- ethanolamides and their corresponding membrane precursors, phosphatidylethanolamides, also was observed during gametophyte development. Pharmacological studies revealed that AEA specifically inhibits polarized tip growth, which justifies the low endogenous levels of AEA in protonemata. To further determine the physiological relevance of these 20C PU-NAEs, a fatty acid amide hydrolase that catabolizes NAEs has been heterologously characterized. Furthermore, generation of metabolite mutants with altered NAE levels is underway. Overall, we identified two novel NAEs, AEA and EPEA in Physcomitrella, which may play an important role in regulation of moss growth and development, although the underlying mechanism is still unclear.
Kilaru, Aruna; Haq, Imadadul; Chilufya, Jedaidah; Devaiah, Shivakumar; Shinde, Sushas; and Welti, Ruth. (false). 2017. Novel Polyunsaturated N-acylethanolamines (NAE) and Their Role in Physcomitrella Patens. International Moss Society Meeting, Honolulu, Hawaii.