Huntingtin Interacting Protein 1 (HIP1)

Huntingtin Interacting Protein is a protein that interacts with the huntingtin protein contain a domain homologous to the death effector domains (DED) found on proteins involved in apoptosis. It is believed that accumulation of high levels of the free form of this protein (free as in dissociated from the huntingtin and free to bind other key protein(s)) in the cell is one of the mechanisms by which neuron cell death is caused in Huntington's Disease (via the caspase-3 route). The role of Hip-1 in caspase mediated cell death remains unclear. Huntingtin interacting protein 1 (HIP1) was first identified by Wanker et al. in 1997. HIP1 was found to bind to Htt in an N-terminal dependent manner, and co-localise with Htt in the CNS although the nature of this interaction with respect to muHtt was not identified.