The Hidden side of SERPINB1/Leukocyte Elastase Inhibitor

Abstract

International audienceSERPINB1, also called Leukocyte Elastase Inhibitor (LEI) is amember of the clade B of SERPINS . It is an intracellular protein andacts primarily to protect the cell from proteases released into thecytoplasm during stress. Its role in inflammation is clear due to itsinvolvement in the resolution of chronic inflammatory lung and boweldiseases. LEI/SERPINB1 intrinsically possesses two enzymatic activities:an antiprotease activity dependent on its reactive site loop, which isanalogous to the other proteins of the family and an endonucleaseactivity which is unveiled by the cleavage of the reactive site loop. Theconformational change induced by this cleavage also unveils a bipartitenuclear localization signal allowing the protein to translocate to thenucleus. Recent data indicate that it has also a role in cell migrationsuggesting that it could be involved in diverse processes like woundhealing and malignant metastases