CLIC6, a member of the intracellular chloride channel family, interacts with dopamine D(2)-like receptors.
To identify proteins interacting with the C-terminal cytoplasmic tail of the dopamine D(3) receptor (D(3)R), we used the two-hybrid system to screen a rat brain cDNA library. We isolated three partial cDNAs encoding, respectively, for the MUPP1 multi-PDZ protein, for the N-terminal region of radixin, for GIPC and for a 160-amino acid open reading frame sharing high homology with the human CLIC6, also identified as parchorin in rabbit. In the two-hybrid system, CLIC6 was also able to interact with the D(2)R and D(4)R. The interaction between D(3)R and CLIC6 was confirmed by the use of a GST-D(3)R C-terminus fusion protein and COS cell extracts transiently expressing epitope-tagged CLIC6. In adult rat brain, CLIC6 mRNA expression was restricted to the choroid plexus, the striatal proliferative subventricular zone and the cerebellum where it is co-expressed with the D(3)R in the Purkinje cells of the lobules IX and X. CLIC6 mRNA was also detected in the pituitary in the posterior lobe and in cells co-expressing the D(2)R at the border between the intermediate and anterior lobes. In transfected HEK293 cells, D(3)R and CLIC6 co-localized at the plasma-membrane. No effect of CLIC6 transfection was observed on either intracellular chloride concentration or D(3)R/D(2)R-mediated response. In two-hybrid system, CLIC6 also interacted with MUPP1 and radixin but not GIPC, suggesting it could take part in a complex with D(2)-like receptors, not only by direct interaction with their C-termini, but also through interactions with scaffolding proteins.
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D016466:CHO Cells; D019556:COS Cells; D002352:Carrier Proteins; D002462:Cell Membrane / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D002522:Chlorocebus aethiops; D002831:Choroid Plexus / Q000378:metabolism; D003001:Cloning, Molecular; D006224:Cricetinae; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D013936:Thymidine / Q000378:metabolism; D014162:Transfection; D020798:Two-Hybrid System Techniques; D015003:Yeasts
C479066:CLIC6 protein, rat; D002352:Carrier Proteins; D018118:Chloride Channels; D002712:Chlorides; C493593:DRD3 protein, human; C493595:Drd3 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; C111442:MPDZ protein, human; D008565:Membrane Proteins; C491749:Mpdz protein, rat; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D010446:Peptide Fragments; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013936:Thymidine