hnRNP K enhances hnRNP A1 expression. (A) WB analysis of HEK293T cells overexpressing FLAG-hnRNP K. Quantification of relative expression levels of hnRNP A1 and hnRNP A2/B1 is shown (n = 3 for each group). (B) Immunocytochemistry of HeLaS3 cells overexpressing FLAG-hnRNP K. FLAG (magenta), hnRNP A1 or hnRNP A2/B1 (green), and Hoechst (blue). Arrowheads indicate FLAG-positive cells, while arrows indicate FLAG-negative cells. Scale bar: 10 μm. (C) Quantification of nuclear hnRNP A1 or hnRNP A2/B1 fluorescence intensity in FLAG-hnRNP K–positive and –negative cells. A total of 100 FLAG-positive and 100 FLAG-negative cells per group were analyzed. Statistical analyses were performed using Welch’s t test. (D) Comparison of nuclear hnRNP A1 or hnRNP A2/B1 fluorescence intensity in cells with FLAG-hnRNP K localized only in the nucleus (Nuc) versus in both the cytoplasm and nucleus (Cyto+Nuc). For hnRNP A1, Nuc: 52 cells, Cyto+Nuc: 48 cells; for hnRNP A2/B1, Nuc: 64 cells, Cyto+Nuc: 35 cells. Statistical analyses were performed using Welch’s t test. (E) WB analysis of HEK293T cells with hnRNP K KD. Quantification of relative expression levels of hnRNP K or hnRNP A1 is shown (n = 3 for each group). In A and E, data are normalized to β-actin. Statistical analyses were performed using one-way ANOVA followed by Dunnett’s test (A) or Welch’s t test (E). All graphs show the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. Source data are available for this figure: SourceData F6.