Skip to main content
. 2007 Jul 4;27(27):7318–7328. doi: 10.1523/JNEUROSCI.1831-07.2007

Figure 2.

Figure 2.

Cdk5 phosphorylates huntingtin at S1181 and S1201 in neurons. A–D, Immunoblotting experiments are performed using the anti-P-htt–S1181, anti-P-htt–S1201, anti-htt (4C8), anti-Cdk5, anti-p35, and anti-β-actin antibodies as indicated. A, To assess the specificity of the phospho-antibodies, 1301–17Q, 1301–17Q–S1181A, and 1301–17Q–S1201A are expressed in HEK 293T cells. B, Cdk5/p35 and Cdk5/p25 are expressed in HEK 293T cells. Quantification reveals a statistically significant increase in phosphorylation at S1181 and S1201 of endogenous htt in the presence of Cdk5/p35 and Cdk5/p25. C, D, Htt phosphorylation at S1181 and S1201 is significantly inhibited by decreasing Cdk5 levels by RNA interference (pSuper–Cdk5) or by roscovitine treatment. SH-SY5Y cells (C) and primary cultures of striatal neurons (D) were transfected with pSuper–Cdk5 or treated with roscovitine (10 μm, 3 h). Quantifications reveal decreased phosphorylations when Cdk5 activity is diminished. *p < 0.05; **p < 0.01; ***p < 0.001.