title: Interaction of LDL receptor-related protein 4 (LRP4) with postsynaptic scaffold proteins via its C-terminal PDZ domain-binding motif, and its regulation by Ca/calmodulin-dependent protein kinase II.
abstract: We cloned here a full-length cDNA of Dem26[Tian et al. (1999)Mol. Brain Res., 72, 147-157], a member of the low-density lipoprotein (LDL) receptor gene family from the rat brain. We originally named the corresponding protein synaptic LDL receptor-related protein (synLRP) [Tian et al. (2002) Soc. Neurosci. Abstr., 28, 405] and have renamed it LRP4 to accord it systematic nomenclature (GenBank(TM) accession no. AB073317). LRP4 protein interacted with postsynaptic scaffold proteins such as postsynaptic density (PSD)-95 via its C-terminal tail sequence, and associated with N-methyl-D-aspartate (NMDA)-type glutamate receptor subunit. The mRNA of LRP4 was localized to dendrites, as well as somas, of neuronal cells, and the full-length protein of 250 kDa was highly concentrated in the brain and localized to various subcellular compartments in the brain, including synaptic fractions. Immunocytochemical study using cultured cortical neurons suggested surface localization in the neuronal cells both in somas and dendrites. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) phosphorylated the C-terminal cytoplasmic region of LRP4 at Ser1887 and Ser1900, and the phosphorylation at the latter site suppressed the interaction of the protein with PSD-95 and synapse-associated protein 97 (SAP97). These findings suggest a postsynaptic role for LRP4, a putative endocytic multiligand receptor, and a mechanism in which CaMKII regulates PDZ-dependent protein-protein interactions and receptor dynamics.
authors.affiliation: Department of Neuroplasticity, Institute on Ageing and Adaptation, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
authors.forename: Qing-Bao
authors.initials: QB
authors.lastname: Tian
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamauchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakagami
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Shoko
authors.initials: S
authors.lastname: Miyazawa
authors.forename: Kohzo
authors.initials: K
authors.lastname: Nakayama
authors.forename: Fuminori
authors.initials: F
authors.lastname: Saitoh
authors.forename: Jing-Ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Lu
authors.forename: Hisatake
authors.initials: H
authors.lastname: Kondo
authors.forename: Shogo
authors.initials: S
authors.lastname: Endo
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern / Q000379:methods; D001921:Brain / Q000166:cytology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000502:physiology*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012694:Serine / Q000378:metabolism; D013997:Time Factors; D014162:Transfection / Q000379:methods
chemical_list: D026503:Low Density Lipoprotein Receptor-Related Protein-1; D009419:Nerve Tissue Proteins; C033652:postsynaptic density proteins; D012694:Serine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases