Journal: The Journal of Neuroscience
Article Title: STIM1 Is Required for Remodeling of the Endoplasmic Reticulum and Microtubule Cytoskeleton in Steering Growth Cones
doi: 10.1523/JNEUROSCI.2496-18.2019
Figure Lengend Snippet: STIM1 is required for microtubule-ER remodeling and calcium signals in filopodia. A–F, STIM1-CTRL and STIM1-KD neurons were cotransfected with BiP-mCherry-KDEL (ER membrane marker) and EB3-YFP. Images of (A) STIM1-CTRL and (B) STIM1-KD growth cones expressing KDEL (red) and EB3 (green). Scale bar, 5 μm. Ci, Di, KDEL and EB3 localization in single filopodia (outlined). Cii, Dii, Representative kymographs of KDEL (red) and EB3 (green) protrusion into STIM1-CTRL (C) and STIM1-KD (D) filopodia, displayed over 20 and 40 s, respectively. Scale bars, 500 nm. E, The percentage of filopodia with a KDEL signal in STIM1-CTRL filopodia (n = 7) was not significantly different from STIM1-KD filopodia (n = 12) (p = 0.0224, Kruskal–Wallis test). F, The distance EB3 dashes with KDEL signals protruded into filopodia was significantly reduced in STIM1-KD compared with STIM1-CTRL filopodia (***p = 0.003, Kruskal–Wallis test, see Movies 3, 4, 5, 6). G, H, STIM1-CTRL (n = 12) and STIM1-KD (n = 16) sensory neurons were cotransfected with ER-GCaMP6–150 (Ca2+ER reporter) and EB3-tdTomato. Gi, Hi, ER-GCaMP6 (green) and EB3 (red) in filopodia (outlined). Gii, Hii, Representative kymographs of ER-GCaMP6 (green) and EB3 (red) protrusion into STIM1-CTRL (Gii) and STIM1-KD (Hii) filopodia, displayed over 20 and 40 s, respectively. Scale bars, 500 nm. I–M, STIM1-CTRL and STIM1-KD sensory neurons were cotransfected with BiP-mCherry-KDEL and ER-GCaMP6. Images of (I) STIM1-CTRL and (J) STIM1-KD growth cones expressing KDEL (red) and ER-GCaMP6 (green). Scale bar, 5 μm. Ki, Li, ER-GCaMP6 (green) and KDEL (red) in filopodia (outlined). Kii, Lii, Representative kymographs of ER-GCaMP6 (green) and KDEL (red) as ER membrane extends into STIM1-CTRL(Kii) and STIM1-KD (Lii) filopodia, displayed over 20 and 40 s, respectively. Scale bar, 500 nm. M, The filopodial ER-GCaMP6 signal, ΔF/F normalized to KDEL signal, and averaged over 20 s was significantly reduced in STIM1-KD (n = 15) compared with STIM1-CTRL filopodia (n = 16, ****p = 0.00003, Student's t test, see Movies 7, 8).
Article Snippet: EB3-YFP was transfected using nucleofection (Lonza Walkersville) or with magnetic particles following the manufacturer's instructions (NeuroMag; catalog #NM50200, Oz Biosciences) or subcloned into BamHI and NheI restriction sites of a second-generation lentiviral construct containing the neuron-specific hSyn promoter.
Techniques: Marker, Expressing