Localization of the pannexin1 protein at postsynaptic sites in the cerebral cortex and hippocampus.
Pannexins (Panx) constitute a new family of gap junction type proteins. Functional expression in paired Xenopus oocytes indicated that pannexins are capable of forming communicating junctions but also proved to be active in forming of unopposed hemichannels. In the vertebrate brain pannexins have been found in neurons. However, the subcellular cerebral localization of pannexin proteins which could gain first clues on their putative function is essentially unknown. Here we demonstrate by light and electron microscopical immunohistochemistry that Panx1 reveals postsynaptic localization in rodent hippocampal and cortical principal neurons accumulating at postsynaptic densities. The postsynaptic localization was corroborated by co-localization of Panx1 with postsynaptic density protein 95 (PSD-95), a prominent postsynaptic scaffolding protein, in hippocampal neurons expressing tagged versions of these proteins. The asymmetric synaptic distribution of Panx1 suggests that it may function in neurons as non-junctional channels (pannexons) at postsynaptic sites and comprises a novel component of the postsynaptic protein complex.
Zoidl
G
G
Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Universitystreet 150, D-44780 Bochum, Germany.
Petrasch-Parwez
E
E
Ray
A
A
Meier
C
C
Bunse
S
S
Habbes
H-W
HW
Dahl
G
G
Dermietzel
R
R
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism; D017630:Connexins; D000076122:Disks Large Homolog 4 Protein; D051528:Guanylate Kinases; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission / Q000379:methods; D016253:Microscopy, Immunoelectron / Q000379:methods; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism / Q000648:ultrastructure*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure
D017630:Connexins; D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C503631:Panx1 protein, mouse; D051528:Guanylate Kinases