Figure 5
From: Huntingtin mediates dendritic transport of β-actin mRNA in rat neurons
Motor proteins kinesin-1 and dynein are involved in the dendritic transport of β-actin mRNA.
The left part of each image is the proximal part of the dendrite. DHC: dynein heavy chain. Scale bar: 5.0 μm. (a) KIF5A and dynein co-localize with β-actin mRNA in rat cortical neurons (DIV 9). The arrows indicate the co-localization of three targets. UKHC: kinesin-1 heavy chain. (b) Co-localization of Htt, β-actin mRNA and Phos-Htt in rat cortical neurons (DIV 9). (c) Live cell co-trafficking of KIF5A with β-actin mRNA in rat cortical neurons was imaged over 509.6 seconds. β-actin mRNA (detected by NLS-MS2-RFP) is in red and KIF5A (GFP) in green. The arrow indicates an mRNA granule that moves anterogradely along the dendrite. The distance that the granule traveled was 1.39 μm. The velocity of the granule is 0.013 μm/s. (d) Co-trafficking of DIC with β-actin mRNA in rat cortical neurons was imaged live over 1040.4 seconds. β-actin mRNA (detected by NLS-MS2-RFP) is in red and DIC (EGFP) in green. The arrow indicates an mRNA granule that moves retrogradely along dendrites. The distance that the granule traveled was 1.57 μm. DIC: dynein intermediate chain. (e–f) Knockdown of KIF5A or DHC decreases β-actin mRNA levels in rat neurons. DIV 4 cortical neurons were infected with a lentivirus expressing scrambled shRNA, shRNA-KIF5A, or shRNA-DHC and probed at DIV 8 for β-actin mRNA (red), KIF5A or DHC (blue) and GFP (green). The left part of each image is the proximal part of the dendrite. The right panel shows quantitative analysis of the normalized intensity. The percent shown in parentheses indicates extent of knockdown for KIF5A or DHC and reduction in signal for β-actin mRNA relative to scrambled.
