Protein Class Function | Protein Name | Function of Interacting Protein | Evidence and Site of Interaction | Reference |
---|---|---|---|---|
Signaling modulators | Calmodulin | Interferes with basal and agonist-induced G protein activation | Indirect evidence: calmodulin binds to ICL3 of MOPr; shown to compete with G protein activation by DOPr | Wang et al. (1999) |
Periplakin | Interferes with agonist-induced G protein activation | Evidence of direct interaction by yeast two-hybid involves helix 8 in DOPr C-terminal tail (residues 321–331) | Feng et al. (2003) | |
RGS4 | Interferes with DOPr signaling | Evidence of direct interaction in GST pull down involves residues 311–333 | Georgoussi et al. (2006), Wang et al. (2009) | |
Coimmunoprecipitation assays showed constitutive association not modified by agonist | ||||
Spinophilin | Ubiquitous multidomain scaffold that interact with cytoskeleton: enriched in dendritic spines | Evidence of direct interaction by GST pull down | Fourla et al. (2012) | |
Interaction involves ICL3 and residues 311–333 | ||||
Signaling | STAT5B | Activator of transcription | Evidence of direct interaction established in vitro | Georganta et al. (2010) |
Its release from DOPrs promotes transcription activation of STAT5-dependant genes | Evidence of association in cells by coimmunoprecipitation | |||
Involves interaction with YXXL motif | ||||
Association is ligand-independent and abolished by DOPr activation | ||||
Gα and Gβ subunits are also part of the complex | ||||
Desensitization and trafficking | GRK2 | Desensitization, internalization | Evidence of interaction by coimmunoprecipitation in cells | Li et al. (2003) |
Involves last 31 amino acids in C tail | ||||
Interaction require DOPr activation | ||||
Arrestins | Desensitization, internalization | Evidence of association by BRET | Zhang et al. (2005) | |
Involves IL-3 (amino acids 235–259) and C terminus (amino acids 331–372) | Audet et al. (2012) | |||
Interaction requires DOPr activation | ||||
Glycoprotein M6a | Sorts DOPrs to recycling endosomes | Evidence of interaction by BRET DOPr/M6a | Liang et al. (2008) | |
Presumably involves DOPr TM 4, 5, 6 (in analogy with MOPr) | Wu et al. (2007) | |||
GASP1 | Commits DOPr to lysosomal degradation | Evidence of direct interaction by GST pull down, involves last 50 amino acids in C terminus (including helix 8), evidence also by coimmunoprecipitation | Whistler et al. (2002) | |
Constitutive association | Simonin et al. (2004) | |||
Heydorn et al. (2004) | ||||
NHERF | Mediates NGF-dependant membrane targeting of intracellular DOPrs | Evidence obtained by coimmunoprecipitation | Bie et al. (2010) | |
Site not determined | ||||
Association is NGF dependent | ||||
SNX1 (retromer component) | Not determined | Evidence of direct interaction established in vitro | Heydorn et al. (2004) | |
Involved helix 8 in DOPr C terminus | ||||
Ubiquitination | Ubiquitin | Degradation of misfolded DOPrs, not essential for postendocytic sorting to lysosomes | Evidence obtained in cells by WB (ubiquitin detection) | Petaja-Repo et al. (2001) |
Cytosolic lysines | Tanowitz and Von Zastrow (2002) | |||
Hislop et al. (2009) | ||||
AUP1 | Promotes ubiquitination of misfolded proteins | Evidence obtained in cells by coimmunoprecipitation | Petko et al. (2013) | |
IL-2 (established for MOPr spontaneous association) | Mueller et al. (2008) | |||
SIAH 1, SIAH 2 | RING finger ubiquitin ligases | Evidence obtained in cells by coimmunoprecipitation | Petko et al. (2013) | |
Site of interaction IL-2 (in analogy with MOPr) | ||||
Spontaneous association | Hu et al. (1997) | |||
Biosynthetic pathway | Calnexin | Facilates proper folding of recepor in the ER | Evidence obtained in cells by coimmunoprecipitation | Petäjä-Repo et al. (2002) |
Site not determined | ||||
Spontaneous association | ||||
VAPA | Involved in ER to Golgi transport | Evidence obtained in cells by coimmunoprecipitation | Petko et al. (2013) | |
Site of interactions is IL-2 | ||||
Established in vitro for MOPrs | Peretti et al. (2008) |
AUP1, ancient ubiquitous protein 1; RING, really interesting new gene; SIAH, seven in absentia homolog; SNX1, sorting nexin 1; VAPA, vesicule-associated protein A; WB, western blot.