EURAL PHOSPHOPROTEOMICS OF A CHRONIC HYPOXIA

bstract—Chronic hypoxia is a common clinical event that nduces adaptive responses and can result in behavioral eterioration. The reduction of metabolic rate during hypoxia ay limit overall protein phosphorylation owing to the lack of igh energy phosphate. However, the hypoxia-induced reguation of phosphoproteins is poorly understood. Here, we haracterized the CNS phosphoproteome of Lymnaea stagalis, a freshwater snail that has been used as a model to tudy chronic hypoxia-induced neural depression. After hypxia treatment for 4 days, the motor behavior of the snail was uppressed. Electrophysiological measurements from Pedal (PeA) interneurons showed that hypoxia increased the requency of spontaneous postsynaptic excitatory potentials sEPSPs), but reduced the firing frequency, the amplitude, nd the half-width duration (APD50) of spontaneous action otentials. Imaging with a fluorescent phosphate label, Pro-Q iamond, revealed that the neuronal phosphoprotein level as reduced after the hypoxia treatment. The hypoxia-inuced changes in the phosphoproteome of the central ganlia were quantified using one-dimensional gel-electrophoreis by comparing the fluorescence intensity ratio of phosphoabeled phosphoproteins versus total proteins between the ypoxia and control groups. We analyzed 16 protein bands: ight showed decreased phosphorylation levels after hypxia treatment, and eight did not change. Using mass specrometry analysis and protein database matching we found hree phosphoproteins that may be associated with chronic ypoxia-induced neuronal adaptive response of the snail. his is the first proteomic screening for neural phosphoproeins in chronic hypoxia. © 2009 IBRO. Published by Elsevier td. All rights reserved.