508 Alternative splicing of Lysyl Oxidase-Like 4 in ovarian carcinoma

Abstract

Lysyl oxidase (LOX) is a copper-containing amine oxidase belonging to a heterogeneous family of enzymes that oxidize primary amine substrates to reactive aldehydes. It has been traditionally known for one function—the extracellular catalysis of lysine-derived cross-links in fibrillar collagens and elastin. Diverse roles have been attributed to lysyl oxidase and its novel activities cover a spectrum of diverse biological functions, such as developmental regulation, tumor suppression, cell motility, and cellular senescence. Lysyl oxidase has also been shown to have both intracellular and intranuclear locations. The multifunctional properties of lysyl oxidase (LOX) and the discovery of three novel members of this amine oxldase family—LOX-like (LOXL), LOXL2, and LOXL3—indicate the possibility that these varied functions are performed in both intracellular and extracellular environments by individual novel members of the LOX amine oxidase family. Structural similarity of the highly conserved copper-blnding and lysyltyrosylquinone cofactor sites among the LOX and LOX-like proteins results in similar amine oxldase activities. However, specific novel functions, such as a potential role in cell adhesion and cell growth control, is determined by other conserved domains such as the cytokine receptor-like domain that is shared by all LOXs and by multiple scavenger receptor cysteine-rich (SBCR) domains present in LOXL2 and LOXL3.