Figure 2.

Tropomyosin Tpm3.1 Decorates Actin Patches in the AIS

(A) Rat hippocampal neuron expressing YFP-Tpm3.1. Neurons were fixed 8 h post transfection. Anti-ankyrin G served to label the AIS. Patches of YFP-Tpm3.1 can be seen in the AIS (white box) and distally in the axon (yellow box), whereas the somatodendritic domain (cyan box) shows a diffuse, less intense distribution.

(B) Maximum intensity projection of 3D-SIM reconstructions for F-actin and Tpm3.1/2. Arrowheads indicate actin patch. Scale bar: 1 μm.

(C) Actin patch visualized in live hippocampal neuron using PAGFP-actin before photoactivation (pre), immediately after activation (0 s), and the time-points indicated in seconds. Arrowheads indicate actin patch.

(D) Fluorescence decay over time (gray diamonds) of the actin patch in (C) and a double-exponential decay fit (solid black line).

(E) Tpm3.1/2 distribution visualized using anti-γ/9d in the same area after fixation in 4% PFA. The intensity of Tpm3.1/2 immunofluorescence was higher in the region corresponding to the actin patch visualized in (C) (arrowhead). Scale bar: 5 μm.

See also Figure S2.