title: Identification of LRP1B-interacting proteins and inhibition of protein kinase Calpha-phosphorylation of LRP1B by association with PICK1.
abstract: Recent studies show LDL receptor-related protein 1B, LRP1B as a transducer of extracellular signals. Here, we identify six interacting partners of the LRP1B cytoplasmic region by yeast two-hybrid screen and confirmed their in vivo binding by immunoprecipitation. One of the partners, PICK1 recognizes the C-terminus of LRP1B and LRP1. The cytoplasmic domains of LRP1B are phosphorylated by PKCalpha about 100 times more efficiently than LRP1. Binding of PICK1 inhibits phosphorylation of LRP1B, but does not affect LRP1 phosphorylation. This study presents the possibility that LRP1B participates in signal transduction which PICK1 may regulate by inhibiting PKCalpha phosphorylation of LRP1B.
authors.affiliation: Division of Gene Function in Animals, Nara Institute of Science and Technology, Takayama, Ikoma, Nara, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shiroshima
authors.forename: Chio
authors.initials: C
authors.lastname: Oka
authors.forename: Masashi
authors.initials: M
authors.lastname: Kawaichi
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; C486644:Lrp1b protein, mouse; D009687:Nuclear Proteins; C498297:PICk1 protein, human; D011973:Receptors, LDL; D025521:Tumor Suppressor Proteins; D051571:Protein Kinase C-alpha