Fig.4.

Rac and p85α PI 3-kinase both co-immunoprecipitate with endogenous Huntingtin. (a) Western blot analysis of Huntingtin (Htt) immunoprecipitated from wild-type (WT) and Q140/Q140 (HD) adult mouse brain using anti-Huntingtin antibody MAB2166. Eluates were analyzed using two gel formats. Blot from a 3–8% SDS-PAGE gel was probed with polyclonal anti-Huntingtin Ab1 to confirm presence of full-length Huntingtin (∼350 kDa) (top). Blot from 4–12% SDS-PAGE gel was probed for p85 regulatory subunit of PI 3-kinase (middle blot, arrow) and Rac1 (bottom blot, arrow). The mouse IgG light chains (indicated) are recognized by the secondary antibody on the Rac1 probe. Vertical lines indicate where lanes were removed from same gel.