FHL2 interacts with both ADAM‐17 and the cytoskeleton and regulates ADAM‐17 localization and activity

ADAM-17 is a metalloprotease- disintegrinresponsible for the ectodomainshedding of several transmembrane proteins. Using the yeast two-hybrid system, we showed that ADAM-17 interacts with the Four and Half LIM domain2 protein ( FHL2), a LIM domainprotein that is involved in multiple protein-protein interaction. We demonstrated that this interaction involved the amino-acid sequence of ADAM-17 from position 721 to739. In the cardiomyoblast cells H9C2, ADAM-17 and FHL2colocalize with the actin-based cytoskeletonand we showed that FHL2binds both ADAM-17 and the actin-based cytoskeleton. We found that mainly the mature form of ADAM-17 associates with the cytoskeleton, although the maturation of ADAM-17 by furinis not necessary for its binding to the cytoskeleton. Interestingly, less ADAM-17 was detected at the surface of wild-type mouse macrophages compared to FHL2deficient macrophages. However, wild-type cells have a higher ability to release ADAM-17 substrates under PMA stimulation. Altogether, these results demonstrate a physical and functional interaction between ADAM-17 and FHL2that implies that FHL2has a role in the regulation of ADAM-17. J. Cell. Physiol. 208: 363–372, 2006. © 2006 Wiley-Liss, Inc.