Fig. 3: The nuclear import of TANGO6 is assisted by SNARE complex, ER and KPNB1.

a Western blot analysis of TANGO6 and RPB2 distribution in cytoplasm (C) and nucleus (N) during different interphases of cell cycle. b The immunofluorescent staining images of TANGO6, COPA and Calnexin. The bottom panels are the magnified field of boxed regions. The white arrowheads indicate the TANGO6⁺COPA^- dots co-localized with Calnexin⁺ signals. Scale bar, 10 μm. c The immunofluorescent staining images of HA-TANGO6 and Calnexin. The white arrowheads indicate merged signals. Scale bar, 10 μm. d Western blot analysis of TANGO6 in the fractions of cis-Golg, trans-Golgi and ER. ER, endoplasmic reticulum. e The immunofluorescent staining images of TANGO6 and COPA when knocking down NSF. Scale bar, 20 μm. f The immunofluorescent staining images of TANGO6 after knocking down LRRC59. The white arrowheads indicate nuclear TANGO6⁺ signals. Scale bar, 20 μm. g The immunofluorescent staining images of TANGO6 and Lamin B1. The white arrowheads indicate the TANGO6⁺ signals inside the space between Lamin B1⁺ dots. Scale bar, 10 μm. The diagram of NLS fused with GFP (h) and the fluorescent images of GFP fused with or without NLS element (i). The white dashed lines indicate the nucleus. NLS, nuclear localization signal. aa amino acid. Scale bar, 10 μm. j The diagram of constructs with different NLS mutations. k The immunofluorescent staining images of HA after transfecting various constructs in j. FL full length. D delete. Scale bar, 10 μm. Co-immunoprecipitation of KPNB1 with TANGO6 (l) or TANGO6 ^ΔNLS (delete NLS) (m). IP immunoprecipitation. n The immunofluorescent staining images of TANGO6 when knocking down KPNB1. The right panels are amplified images of boxed region. The white arrowheads indicate the TANGO6⁺ signals in nucleus, Scale bar, 20 μm. o The schematic diagram of TANGO6 nuclear import process. COPI vesicle dwelled TANGO6 is derived from cis-Golgi and moves to ER via the retrograde transport that is mediated by SNARE. The subsequent nuclear entry of TANGO6 is assisted by its NLS and KPNB1. The models were created with BioRender.com. Source data are provided as a Source Data file.