Abstracts of Poster Sessions

Background: Excitatory amino acid carrier 1 (EAAC1) is a glutamate transporter found in neuronal tissues and is extensively expressed in the retina. EAAC1 plays a role in a variety of neural functions, but its biological functions in the retina has not been fully determined. The purpose of this study was to identify proteins regulated by EAAC1 in the retina of mice. To accomplish this, we used a proteomics-based approach to identify proteins that are upor down-regulated in EAAC1-deficient (EAAC1-/-) mice. Results: Proteomic analyses and two-dimensional gel electorphoresis were performed on the retina of EAAC1-/mice, and the results were compared to that of wild type mice. The protein spots showing significant differences were selected for identification by mass spectrometric analyses. Thirteen proteins were differentially expressed; nine proteins were up-regulated and five proteins were down-regulated in EAAC1-/retina. Functional clustering showed that identified proteins are involved in various cellular process, e.g. cell cycle, cell death, transport and metabolism. Conclusion: We identified thirteen proteins whose expression is changed in EAAC-/mice retinas. These proteins are known to regulate cell proliferation, death, transport, metabolism, cell organization and extracellular matrix. Background Glutamate is an excitatory neurotransmitter but high extracellular concentrations of glutamate leads to neuronal death by apoptosis [1]. Therefore, the glutamate concentration outside neuronal cells must be maintained at low levels, and the concentration is controlled by excitatory amino acid transporters (EAATs). There are five types of EAATs, EAAT1 through EAAT5 [2-5], and the sites of expression of each is different in the central nervous system. Glutamate-aspartate transporter (GLAST) or EAAT1 and glutamate transporter 1 (GLT-1) or EAAT2 are located in glial cells, and GLT-1 is also found in presynaptic terminals. Excitatory amino acid carrier 1 (EAAC1) or EAAT3 and EAAT4 are expressed in the postsynaptic terminals. Published: 21 August 2007 Proteome Science 2007, 5:13 doi:10.1186/1477-5956-5-13 Received: 7 March 2007 Accepted: 21 August 2007 This article is available from: http://www.proteomesci.com/content/5/1/13 © 2007 Okumichi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.