FHL2 fused with biotin ligase shuttles between focal adhesions and the nucleus in a myosin II-dependent manner

Four-and-a-half LIM domains 2 (FHL2) is a molecule that plays a key role in cell proliferation in response to mechanical signals. It shuttles between focal adhesions (FAs) or stress fibers (SFs) and the nucleus in a force-dependent manner. FHL2 interacts with other cytoskeletal molecules at FAs and SFs, but FHL2 interacts with transcriptional factors in the nucleus. This leads to modulation of gene expression for cell proliferation. However, the overall picture of interacting proteins with FHL2 at different regions is poorly understood. Here, we report a stable cell line that expresses FHL2-GFP-BirA, a fusion protein of FHL2 with biotin ligase. FHL2-GFP-BirA localizes at the FAs but accumulates in the nucleus after myosin II inhibition, exhibiting behavior similar to endogenous FHL2. These results suggest that the BioID technique can be used to identify proteins interacting with FHL2 under different mechanical conditions.