The LIM domain protein FHL1C interacts with tight junction protein ZO-1 contributing to the epithelial–mesenchymal transition (EMT) of a breast adenocarcinoma cell line

• Published in: Gene 2014-06, Vol.542 (2), p.182-189
• Main Authors: Zhao, Jun-Long, Liang, Shi-Qian, Fu, Wei, Zhu, Bing-Ke, Li, San-Zhong, Han, Hua, Qin, Hong-Yan
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Breast adenocarcinoma cell line; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cell Line, Tumor; Cell Nucleus - metabolism; Epithelial-Mesenchymal Transition; Female; FHL1C; Humans; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; LIM Domain Proteins - genetics; LIM Domain Proteins - metabolism; Muscle Proteins - genetics; Muscle Proteins - metabolism; PDZ Domains; Protein Interaction Domains and Motifs; Protein Structure, Tertiary; Protein Transport; ZO-1; Zonula Occludens-1 Protein - genetics; Zonula Occludens-1 Protein - metabolism
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2014.03.036

FHL1C is a LIM domain protein that has been implied in transcription regulation through interacting with other proteins, such as RBP-J, the critical transcription factor of the Notch signaling pathway. The LIM domain is a protein–protein interaction interface, suggesting that FHL1C could bind other proteins to enable its functions. In order to explore the interacting proteins with FHL1C, in this study we screened FHL1C-interacting proteins by using immunoprecipitation and mass spectrometric analysis. ZO-1, a member of the Zonula occludens proteins that constitute tight junctions, was sorted out as one candidate by using these techniques. Furthermore, we confirmed the interaction between FHL1C and ZO-1 in cells by using the mammalian two-hybrid assay and the co-immunoprecipitation assay, and verified that ZO-1 could interact with FHL1C through the PDZ domains of ZO-1. Moreover, with immunofluorescence staining, we found that FHL1C could induce ZO-1 translocating into nucleus. With a breast adenocarcinoma cell line MCF7, we showed that the interaction between FHL1C and ZO-1 could contribute to the epithelial–mesenchymal transition (EMT). Taken together, our study might provide new insight into the function of FHL1C on the regulation of EMT in cancer cells.