Lysyl oxidase: a family of multifunctional proteins

Lysyl oxidase (LOX) is a copper containing amine oxidase traditionally described as a secreted enzyme that crosslinks the extracellular matrix proteins elastin and fibrillar collagens. Recently, multiple novel biological functions have been attributed to LOX and experimental evidence indicates that LOX may have other, intra-cellular and intra-nuclear substrates involved in these functions. Our results suggest that several genetically different lysyl oxidases exist that individually function to perform these roles. We report here the gene structure, chromosomal localization, protein domain structure, evolutionary relationship, tissue specific expression and distribution of these novel lysyl oxidases, LOX, LOXL, LOXL2 and LOXL3 that could serve as a family of proteins present in distinct cellular and tissue locations, each with a related but different function.