Figure 4.
Nuclear translocation of the STAT3ER complex in response to 4HT. a, Characterization of the plasmid construct, which was cloned into the LV. Components include long terminal repeats (LTR), the ψ encapsidation signal, cytomegalic virus (CMV) promoter, STAT3, modified ligand binding site of ER, IRES, GFP, and polyadenylation tail. b–d, Cell transduced with STAT3ER. Green fluorescence (b) reflects ER immunoreactivity (used to visualize STAT3ER), and red fluorescence (c) reflects β3-tubulin immunoreactivity (used to visualize neurons). The images are merged in d. Without stimulation of 4HT, ER immunoreactivity is absent from the nucleus, although abundant in the cytoplasm. e–g, As for b–d, except that 4HT has been added for 40 h. Note that this neuron has ER immunoreactivity in the nucleus. h–k, A cell cotransduced with STAT3ER (blue fluorescence; h) and SOCS3/GFP (GFP fluorescence; i) and immunostained for β3-tubulin (red fluorescence; j). The merged image is in k. Note the absence of STAT3ER in the nucleus despite the addition of 4HT. l, Quantification of nuclear translocation of STAT3ER in DRG neurons in response to 4HT stimulation (means ± SEM; n = 4 cultures; ∗p = 5 × 10−6 by Student's t test). Scale bar, 25 μm.