While recombinant NAPE-PLD catalyzed direct release of N-palmitoylethanolamine from N-palmitoylethanolamine plasmalogen, the same reaction occurred in the brain homogenate of NAPE-PLD-deficient mice, suggesting that this reaction occurs through both the NAPE-PLO-dependent and -independent pathways. Liquid chromatography-mass spectrometry revealed a remarkable accumulation of 1-alkenyl-2-hydroxy-glycero-3-phospho(N-acyl)ethanolamines (lyso pNAPEs) in the brain of NAPE-PLD-deficient mice. We also found that brain selleck screening library homogenate formed N-palmitoylethanolamine, N-oleoylethanolamine, and anandamide

from their corresponding lyso pNAPEs by a Mg(2+)-dependent “lysophospholipase D”. Moreover, the brain levels of alkenyl-type lysophosphatidic adds, the other products from lyso pNAPEs by lysophospholipase D, also increased in NAPE-PLO-deficient mice. Glycerophosphodiesterase GDE1 can hydrolyze glycerophospho-N-acylethanolamines to N-acylethanolamines in the brain. In addition, we discovered that recombinant GDE1 has a weak activity to generate N-palmitoylethanolamine from its corresponding buy NU7441 lyso pNAPE, suggesting that this enzyme is at least in part responsible for the lysophospholipase D activity. These results strongly suggest that brain tissue N-acylethanolamines,

including anandamide, can be formed from N-acylated plasmalogen through an NAPE-PLO-independent pathway as well as by their direct release via NAPE-PLO. (C) 2011 Elsevier B.V. All rights reserved.”
“Tulp1 is a protein of unknown function exclusive to rod and cone photoreceptor cells. Mutations in the gene cause autosomal recessive retinitis pigmentosa in AG-881 supplier humans and photoreceptor degeneration in mice. In tulp1-/- mice, rod and cone opsins are mislocalized, and

rhodopsin-bearing extracellular vesicles accumulate around the inner segment, indicating that Tulp1 is involved in protein transport from the inner segment to the outer segment. To investigate this further, we sought to define which outer segment transport pathways are Tulp1-dependent. We used immunohistochemistry to examine the localization of outer segment proteins in tulp1-/- photoreceptors, prior to retinal degeneration. We also surveyed the condition of inner segment organelles and rhodopsin transport machinery proteins. Herein, we show that guanylate cyclase 1 and guanylate cyclase activating proteins 1 and 2 are mislocalized in the absence of Tulp1. Furthermore, arrestin does not translocate to the outer segment in response to light stimulation. Additionally, data from the tulp1-/- retina adds to the understanding of peripheral membrane protein transport, indicating that rhodopsin kinase and transducin do not co-transport in rhodopsin carrier vesicles and phosphodiesterase does not co-transport in guanylate cyclase carrier vesicles.