Fig 1: CLIC protein changes and interacts with type IV collagen in atrial tissue. (a) Western blot detected the expression of CLIC1, CLIC4, CLIC5 and type IV collagen protein in RA-SR (n = 26), RA-AF (n = 36) and LA-AF (n = 36). Beta-actin was used as the reference protein. The experiment was repeated for three times. For statistical analysis, the data were calculated for the value of mean ± S.D. One-way ANOVA was used for comparing the differences of data among groups. *P < 0.05. (b) IF-staining for CLIC1, CLIC4, and CLIC5 in the atrial tissue. DAPI for nuclear; Alexa Fluor 488 for detecting CLIC4, Alexa Fluor 594 for detecting CLIC5 and Alexa Fluor 633 for detecting CLIC1, far red light was adjusted to yellow one to distinguish with red light. (c) Computational protein structure prediction shows 3D structure of type IV collagen dimer (gray) and its binding site to CLIC1 (red), to CLIC4 (blue), and CLIC5 (green). (d) Interaction between the CLICs and type IV collagen was examined by co-immunoprecipitation. Compared to RA-SR, CLIC1, CLIC4 and CLIC5 combined with type IV collagen tightly in LA-AF and RA-AF.