Fig. 6.

Subcellular localization of the N- and C-terminal sections of ATBF1. HEK293T cells were transfected with a HA-tagged full-length ATBF1 cDNA expression vector to observe ATBF1 under the confocal microscopy. An anti-ATBF1 antibody (D1-120) detected the middle section of ATBF1 in the nucleus (A1, A3, A4, A5, A7, A8). a, Most (29/30) of the cells expressed HA-tags in the nucleus with the middle part of ATBF1 (A2–A4). One cell (1/30) showed an HA-tag in the cytoplasm in contrast to ATBF1 in the nucleus (A6–A8). Scale bar = 5 μm. b, Schematic explaining the mechanism of abnormal localization of the N-terminal fragment of ATBF1 cleaved from the main sequence of ATBF1. The HA-tagged N-terminal fragment should be shorter than the ATBF1 protein retained in the cytoplasm. The main fragment of ATBF1 containing three NLSs (1387, 2947 and 2987) should be localized in the nucleus. The epitope of D1-120 represents the major section of ATBF1 containing three NLSs