Journal: bioRxiv
Article Title: The axonal ER couples translation and secretion machineries for local delivery of axonal transmembrane proteins to promote axonal development
doi: 10.1101/2025.09.09.674816
Figure Lengend Snippet: (A-C) Schematic showing the Strep-SBP heterodimerization system using Strep-KIFC1 and SBP-SEC23A to relocate axonal ERES components to the soma (A). Representative images of neurons DIV9 co-transfected with SBP-SEC23A and V5-SEC13 in the absence (control) or presence of Strep-KIFC1 (pulled) (B). Quantification of SEC23A and SEC13 puncta in axon (C). (D-E) Representative images of neurons transfected with SBP-SEC23A alone or with Strep-KIFC1 and stained for endogenous SEC31A (D). Quantification of SEC23A and endogenous SEC31A puncta in the axon (E). (F-G) Representative images of neurons transfected with SBP-SEC23A alone or with Strep-KIFC1 and stained for endogenous RTN4 for axonal ER labeling (F). Quantification of average ER intensity in the axon (G). (H-J) Representative images of DIV4 neurons transfected with a fill and the Strep-SBP heterodimerization system for the removal of axonal ERES components (H). Quantification of primary axon length (I) and total axon arborization (J). Arrowheads point to axons. (K-M) Representative images of DIV4 neurons transfected with a fill and scramble shRNA or shRNAs targeting HDLBP, ZW10, NBAS or SEC22B (K). Quantification of primary axon length (L) and total axon arborization (M). Arrowheads point to axons. Data are presented as mean values ± SEM in (C, E, G, I, J, L, M). Individual data points each represent a neuron, and each color per condition represents an independent experiment. ns = non-significant, **p < 0.01, ***p < 0.001, ****p<0.001 comparing conditions to control using Mann-Whitney test in (C, E (SEC23A), G, Ι) or unpaired t-test in (E(α-SEC31Α), J), or Kruskal-Wallis test followed by Dunn’s multiple comparisons test in (L, M). Scale bars represent 10 μm in (B, D, F), 100 μm in overview images in (H, K), and 20 μm in axon crops in (H).
Article Snippet: These primers were used to generate this construct: KIFC1 Fw: 5’ – tacaaagacgatgacgacaagaccggtatcctctggcatgagatgtggcatgaag – 3’ KIFC1 Rv: 5’ – cgctagcttcgaagaattcttacttcctgttggcctgagcagt – 3’ FRB Fw: 5’ – tacaaagacgatgacgacaagaccggtatcctctggcatgagatgtggcatgaag – 3’ FRB Rv: 5’ – gcagcggagccagcggatccctttgagattcgtcggaacacatgataatagagg – 3’ 20aa linker: 5’ – gaattcgccagaaccagcagcagatccagcgccagaacctgcagcggagccagcggatcc – 3’ FLAG tag: 5’ – gctgcaggtcgactctagagccaccatggactacaaagacgatgacgacaagaccggt – 3’ For mCh-FKBP-SEC23A or GFP-FKBP-SEC23A, SEC23A was PCR amplified from EGFP-SEC23A (Addgene plasmid #66609) and 2x FKBP was amplified from mCh-FKBP2x-RTN4.
Techniques: Transfection, Control, Staining, Labeling, shRNA, MANN-WHITNEY