LIM-only protein FHL3 interacts with CDC25B2 phosphatase

• Published in: Experimental cell research 2003-04, Vol.285 (1), p.99-106
• Main Authors: Mils, Valérie, Yuen Lee, Simon Ming, Joly, Willy, Hang, Eric Wong Chi, Baldin, V.éronique, Waye, Mary Miu Yee, Ducommun, Bernard, Tsui, Stephen Kwok Wing
• Format: Article
• Language: English
• Subjects: Animals; cdc25 Phosphatases - genetics; cdc25 Phosphatases - metabolism; CDC25B; Cell cycle; Cell Cycle - physiology; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Line; Cell Nucleus - metabolism; Cellular Biology; Fluorescence Resonance Energy Transfer; Focal Adhesions - metabolism; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Intracellular Signaling Peptides and Proteins; Life Sciences; LIM Domain Proteins; LIM-only protein; Protein Binding; Protein Isoforms - genetics; Protein Isoforms - metabolism; Recombinant Fusion Proteins - metabolism; Subcellular Processes; Two-Hybrid System Techniques
• ISSN: 0014-4827; 1090-2422
• DOI: 10.1016/S0014-4827(03)00018-1

LIM domain proteins are important regulators of the growth, determination, and differentiation of cells. In this report, FHL3 (human four-and-a-half LIM-only protein 3) is shown to interact with human phosphatase CDC25B, a cell cycle regulator involved in the control of G2/M. We found that this interaction was specific to the CDC25B2 isoform. Deletion and point mutation studies indicated that the second LIM domain of FHL3 was essential for this interaction. FRET experiments in C2C12 cells showed that, although both proteins were colocated in the cytoplasm and the nucleus, they interacted only in the nucleus. Finally, we showed that FHL3 binding impaired neither CDC25B2 phosphatase activity nor its localization. Further work is now needed to elucidate the consequences of this interaction on myoblast fate decision and cycle control.