Scientific context
Postsynaptic Density protein 95 (PSD95), also known as Synapse associated protein 90kDa, is a member of the membrane-associated guanylate kinase (MAGUK) family of proteins. PSD95 is a scaffolding protein and is involved in the assembly and function of the postsynaptic density complex (1). These family members consist of an N-terminal variable segment followed by three amino-terminal PDZ domains, an upstream SH3 domain and an inactive carboxyl-terminal guanylate kinase (GK) domain. The first and second PDZ domain localize NMDA receptors and K+ channels to synapses, and the third binds to neuroligins which are neuronal cell adhesion molecules that interact with b-neurexins and form intercellular junctions. PSD-95 also binds to neuronal nitric oxide synthase, possibly through interactions between PDZ domains present on both proteins (2). Thus different PDZ domains of PSD-95 might be specialized for distinct functions (3, 4). PSD95 participates in synaptic targeting of AMPA receptors through an indirect manner involving Stargazin and related transmembrane AMPA receptor regulatory proteins (TARPs) (5). The protein is implicated in experience dependent plasticity and plays an indispensable role in learning (6). Mutations in PSD95 are associated with autism (7).
Bibliography
1. Chetkovich D.M., Bunn R.C., Kuo S.H., Kawasaki Y., Kohwi M., and Bredt D.S. (2002) J Neurosci. 22(15): 6415-25. 2. Cao J., Viholainen J.I., Dart C., Warwick H.K., Levland M.L. and Courtney M.J. (2005) J Cell Biol. 168(1): 117-26. 3. Kennedy M. (1997) Trends in Neurosci. 6: 264-268. 4. Irie M. et al. (1997) Science 277(5331): 1511-5. 5. Cai C. et al. (2006) J Biol Chem. 281: 4267-73. 6. Yao W.D. et al. (2004) Neuron 41: 625-38. 7. Cline H. (2005) Curr Biol. 15: R203-5.
Representative figure legend
Immunocytochemistry/Immunofluorescence analysis using Mouse Anti-PSD95 Monoclonal Antibody, Clone 6G6 (SMC-122). Tissue: HaCaT cells. Species: Human. Fixation: Cold 100% methanol for 10 minutes at -20°C. Primary Antibody: Mouse Anti-PSD95 Monoclonal Antibody (SMC-122) at 1:100 for 1 hour at RT. Secondary Antibody: FITC Goat Anti-Mouse (green) at 1:50 for 1 hour at RT. Localization: Junction staining. Immunocytochemistry/Immunofluorescence analysis using Mouse Anti-PSD95 Monoclonal Antibody, Clone 6G6 (SMC-122). Tissue: dissociated hippocampal neurons. Species: Rat. Fixation: Cold 4% paraformaldehyde/0.2% glutaraldehyde in 0.1M sodium phosphate buffer. Primary Antibody: Mouse Anti-PSD95 Monoclonal Antibody (SMC-122) at 1:1000 for 12 hours at 4°C. Secondary Antibody: FITC Goat Anti-Mouse IgG (green) at 1:50 for 30 minutes at RT. Magnification: 10X. Courtesy of: Mary Kennedy, Caltech. Western Blot analysis of Rat brain membrane lysate showing detection of PSD95 protein using Mouse Anti-PSD95 Monoclonal Antibody, Clone 6G6 (SMC-122). Primary Antibody: Mouse Anti-PSD95 Monoclonal Antibody (SMC-122) at 1:1000. Mouse Anti-PSD95 Antibody [6G6] used in Immunocytochemistry/Immunofluorescence (ICC/IF) on Human HaCaT cells (SMC-122) Mouse Anti-PSD95 Antibody [6G6] used in Immunocytochemistry/Immunofluorescence (ICC/IF) on Rat dissociated hippocampal neurons (SMC-122) Mouse Anti-PSD95 Antibody [6G6] used in Western Blot (WB) on Rat brain membrane lysate (SMC-122)