title: Polycystin-1 can interact with homer 1/Vesl-1 in postnatal hippocampal neurons.
abstract: Polycystin-1 (PC-1) has been identified as critical to development of the nervous system, but the significance of PC-1 expression in neurons remains undefined, and little is known of its roles outside the kidney, where mutation results in autosomal dominant polycystic kidney disease (ADPKD). In kidney, PC-1 interacts with cadherins, catenins, and its cognate calcium channel polycystin-2 (PC-2), which in turn interacts with a number of actin-regulatory proteins. Because some of the proteins that interact with PC-1 in kidney also participate in synaptic remodeling and plasticity in the hippocampus, we decided to test PC-1's potential to interact with a recently discovered type of plasticity-associated protein (homer 1a/Vesl-1S) in postnatal mouse hippocampus. Homer 1a/Vesl-1S is an activity-induced protein believed to participate in synaptic remodeling/plasticity responses to temporal lobe seizure and learning. Here we report the following. 1) PC-1 contains a homer-binding motif (PPxxF), which lies within its purported cytoplasmic domain. 2) Immunoreactivity for PC-1 (PC-1-ir) is highly colocalized with homer 1a immunoreactivity (H1a-ir) in primary cultured hippocampal neurons. 3) PC-1-ir and H1a-ir are present and appear to be colocalized in mouse hippocampus but not cortex on postnatal day 2 (P2), when higher frequencies of spontaneous activity are normal for hippocampus compared with cortex. 4) An endogenous PC-1-ir band with the correct size for the reported C-terminal G-protein-sensitive domain cleavage product of PC-1 (approximately 150 kDa) coimmunoprecipitates with endogenous homer 1/Vesl-1 proteins from mouse brain, suggesting that PC-1 can interact with homer 1/Vesl-1 proteins in postnatal hippocampal neurons.
authors.affiliation: Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX 76107, USA.
authors.forename: Martha E
authors.initials: ME
authors.lastname: Stokely
authors.forename: Sung-Yong
authors.initials: SY
authors.lastname: Hwang
authors.forename: Ji-yeon
authors.initials: JY
authors.lastname: Hwang
authors.forename: Betty
authors.initials: B
authors.lastname: Fan
authors.forename: Michael A
authors.initials: MA
authors.lastname: King
authors.forename: Kaoru
authors.initials: K
authors.lastname: Inokuchi
authors.forename: Peter
authors.initials: P
authors.lastname: Koulen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western / Q000379:methods; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology*; D000072233:Homer Scaffolding Proteins; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D016900:Neurofilament Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D050396:TRPP Cation Channels / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D000072233:Homer Scaffolding Proteins; D016900:Neurofilament Proteins; D050396:TRPP Cation Channels; C066858:neurofilament protein NF 68