Table 2. Huntingtin Interacting Proteins [39,143-145].
| Name | Protein function | Htt binging region | Influence of mu HTT |
| Transcription | |||
| CA150 | Transcription activator | Unknown | None |
| CBP | Transcription activator | Amino acids 1-588 | Enhances |
| CtBP | Transcription repressor | Unknown | Decreases |
| HYP-A, B | RNA splicing factors | Polyproline | Enhances |
| HYP-C | Transcription factor | Polyproline | Enhances |
| NCOR | Transcription repressor | Amino acids 1-171 | Enhances |
| NF-ĸB | Transcription factor | HEAT repeats | Unknown |
| SP1 | Transcription activator | Amino acids 1-171 | Enhances |
| TAFII130 | Transcription activator | Amino acids 1-480 | None |
| TBP | Basal transcription factor | Unknown | Unknown |
| P53 | Transcription factor | Polyproline | None |
| REST-NRSE | Trascription suppressor | Amino acids 1-548 | Decreases |
| Trafficking and endocytosis | |||
| HAP1 | Trafficking, endocytosis | Amino acids 1-230 | Enhances |
| HIP1 | Endocytosis, pro-apoptotic | Amino acids 1-540 | Decreases |
| HIP14 | Trafficking, endocytosis | Amino acids 1-550 | Decreases |
| PACSIN1 | Endocytosis | Polyproline | Enhances |
| Phosphatidylethanolamine | Phospholipids | Amino acids 171-287 | Enhances |
| PI(3,4,5)P3 | |||
| PSD-905 | Synaptic scaffolding | Unknown | Decreases |
| Signaling | |||
| Calmodulin | Calcium-binding regulatory protein | Unknown | Enhances |
| CIP-4 | Cdc42-related signaling | Amino acids 1-152 | Enhances |
| FIP2 (HYP-L) | GTPase Rab8 interactor | Amino acids 1-550 | Unknown |
| GRb2 | Growth factor signaling | Polyproline | Unknown |
| IP31 | Calcium release channel | Amino acids 1-158 | Enhances |
| SH3GL3 | Endocytosis and vesicle recycling | Polyproline | Enhances |
| RasGAP | Ras GTPase-activating protein | Polyproline | Unknown |
| Metabolism | |||
| Cystathionine b-synthase | Generation of cysteine | Amino acids 1-171 | None |
| GAPDH | Glycolitic enzyme | Polyproline | Enhances |
| gp78 | ER membrane-anchored ubiquitin ligase | HEAT repeats 2/3 | Enhances |
| HIP2 | Ubiquitin-conjugated enzyme | Amino acids 1-540 | None |
| Protein Synthesis | |||
| Gnb211 | Translation (indirect,) ribosomal protein | Unknown | Decreases |
| Myo5a | RNA transport to spines | Unknown | Decreases |
| Rps6 | Translation (direct), Ribosomal protein | Unknown | Decreases |
| Prkra | Translation (indirect), PKR regulation | Unknown | Decreases |
Abbreviations: CA150, co-activator 150; CBP, (cAMP-response element binding protein) binding protein; CIP-4, cdc42-interacting protein 4; Co-IP, co-immunoprecipitation; CtBP, C-terminal-binding protein; FIP2, for 14.7K interacting protein; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; Gnb2l1, guanine nucleotide-binding protein (G protein) polypeptide 2-like 1; gp78, glycoprotein 78; GRB2, growth factor receptor-binding protein 2; GST, glutathione S-transferase; HAP1, htt-associated protein 1; HIP, htt-interacting protein; HYP, htt-yeast partner; IP31, inositol (1,4,5)-trisphosphate receptor type 1; Myo5a, myosin V;A NCOR, nuclear receptor co-repressor; NF-kB, nuclear factor-kB transcription factor; PACSIN1, protein kinase C and casein kinase substrate in neurons 1; [PI(3,4,5)P3] phosphoinositol, (PI) 3,4-bisphosphate, PI 3,5-bisphosphate, and PI 3,4,5-triphosphate; PKR, double-stranded RNA-activated protein kinase; Prkra, interferon inducible double-stranded RNA-dependent protein kinase activator A; PSD- 95, postsynaptic density 95; RasGAP, Ras GTPase-activating protein; REST–NRSE, the repressor element-1 transcription factor–the neuron restrictive silencer element; Rps6, ribosomal protein S6; SH3GL3, SH3-containing GRB2-like protein 3; SP1, specificity protein-1; TAFII130, TBP-associated factor; TBP, TATA box binding protein.