Localization of huntingtin-interacting protein-2 (Hip-2) mRNA in the developing mouse brain

Huntingtin-interacting protein-2 (Hip-2) was identified as a human protein specifically associated with huntingtin in vitro. a gene product affected i n patients with Huntington disease (HD). It is a ubiquitin-conjugating enzy me identical to the previously characterized bovine E2-25k. We identified t he mouse Hip-2 homologue (mHip-2) and examined its distribution patterns in the developing mouse brain ill order to gain an insight into the functiona l significance of the Hip-2 protein in the normal brain as well as in the p athogenesis of HD. As reported with huntingtin, the mHip-2 mRNA expression developed in parallel with neuronal maturation and became distributed widel y in the postnatal mouse brain. This spatiotemporal pattern of mHip-2 mRNA expression resembled that of huntingtin. We further demonstrated that mHip- 2 mRNA was colocalized with huntingtin-like immunoreactivity in a single ne uron. These findings suggested that the Hip-2 interacted with huntingtin in vivo and played an important role in HD pathogenesis. (C) 1999 Elsevier Sc ience B.V. All rights reserved.