Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanding polyglutamine repeat in the IT15 or huntingtin gene. The mechanism(s) of pathogenesis are not known and the wide expression of Huntingtin protein does not explain the selective neuropathology of HD. HAP-1 (Huntingtin-associated protein 1), identified by yeast two hybrid screening, interacts with the huntingtin protein. There are two isoforms of rat HAP1 (HAP1-A and HAP1-B) which differ in the length of their C-terminal regions. Both proteins are highly hydrophilic and their binding to the Huntingtin protein is enhanced by the expanded polyglutamine repeat. Human HAP1 shares 62% amino acid identity with HAP1-A. HAP1 is specifically expressed in the CNS where it is restricted to limbic structures, such as amygdala, hypothalamus, bed nucleus of the stria terminalis, and the septal nucleus. The subcellular association of HAP1 with microtubules and many types of membraneous organelles implicates it in vesicular transport. Thus, the specific neural interaction of HAP1 with Huntingtin protein may lead to abnormalities in vesicular transport that cause the neuropathology of HD.
This antibody is routinely tested by western blot analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.