Partial Characterisation of Murine Huntingtin and Apparent Variations in the Subcellular Localisation of Huntingtin in Human, Mouse and Rat Brain

• Published in: Human molecular genetics Vol. 5; no. 4; pp. 481 - 487
• Main Authors: Wood, Jonathan D., MacMillan, John C., Harper, Peter S., Lowenstein, Pedro R., Jones, A. Lesley
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.04.1996
• Subjects: Adult; Amino Acid Sequence; Animals; Antibodies - immunology; Biological and medical sciences; Blotting, Western; Brain - metabolism; Fundamental and applied biological sciences. Psychology; Gene expression; Humans; Huntingtin Protein; Male; Mice; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nerve Tissue Proteins - metabolism; Nuclear Proteins - metabolism; Peptide Fragments - immunology; Peptide Fragments - metabolism; Rats; Subcellular Fractions; Animal model; Nervous system diseases; Gene product; Rodentia; Huntington disease; Tissue specificity; Gene expression; Cerebral disorder; Genetic disease; Proteins; Vertebrata; Mammalia; Mouse; Central nervous system disease; Degenerative disease; Localization; Extrapyramidal syndrome
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/5.4.481

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by the expansion of a CAG repeat in a gene coding for a protein of unknown function. We have raised a polyclonal antibody against a 12 amino acid peptide (residues 2110–2121 of human huntingtin) which specifically recognises huntingtin on Western blots of human, rat and mouse brain. We have characterised huntingtin expression in the mouse. The protein was detected on Western blots of all mouse tissues examined, with the highest expression seen in brain. Human, mouse and rat brain were fractionated by differential centrifugation and discontinuous Percoll gradients. The fractions were analysed by Western blotting for huntingtin and synaptophysin (a synaptic vesicle localised protein). In mouse brain, huntingtin was localised in the soluble S3 fraction; in rat brain it was localised in the soluble S3 fraction and also in the membrane P2 and P3 fractions; in both normal and HD-affected human brain, huntingtin was membrane bound with a distribution essentially the same as that of synaptophysin. These observed differences in the subcellular localisation of huntingtin between mouse and human brain are important in the context of mouse models for HD.