PTH/PTH-related protein receptor interacts directly with Tctex-1 through its COOH terminus.
COOH-terminal cytoplasmic domains of G protein-coupled receptors (GPCRs) have been shown to carry determinants that control their cell surface localization, internalization, and recycling. In attempts to seek cellular proteins that mediate these processes of PTH/PTH-related protein receptor (PTHR), one of the class B GPCRs, we have found that Tctex-1, a 14kDa light chain of cytoplasmic dynein motor complex, interacts with the COOH-terminal tail of the receptor. A 34-amino-acid stretch of the receptor responsible for binding to Tctex-1 has a bipartite structure consisting of a motif previously implicated in binding of some proteins to Tctex-1 and a putative new consensus sequence. Site-directed mutations or a 20-amino-acid deletion in the bipartite consensus binding sequence abolished the association of the PTHR COOH terminus with Tctex-1 in vitro. A GFP-fused mutant PTHR impaired in binding to Tctex-1 expressed in MDCK cells showed a decreased rate of internalization in response to PTH compared to that of the wild type.
Department of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Maki
M
Sugai
Masaki
M
Saito
Izumi
I
Sukegawa
Yuriko
Y
Katsushima
Yoshitaka
Y
Kinouchi
Norimichi
N
Nakahata
Tooru
T
Shimosegawa
Teruyuki
T
Yanagisawa
Jun
J
Sukegawa
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D002245:Carbon Dioxide / Q000737:chemistry / Q000378:metabolism; D016384:Consensus Sequence; D003593:Cytoplasm / Q000737:chemistry* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000378:metabolism; D008868:Microtubule Proteins / Q000737:chemistry* / Q000378:metabolism*; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D010446:Peptide Fragments; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000819:agonists / Q000737:chemistry* / Q000378:metabolism*; D056427:t-Complex Genome Region
D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D044168:Receptor, Parathyroid Hormone, Type 1; D002245:Carbon Dioxide; C041069:carboxyl radical; D019204:GTP-Binding Proteins