RT Journal Article SR Electronic T1 The conserved metalloprotease invadolysin is present in invertebrate haemolymph and vertebrate blood JF bioRxiv FD Cold Spring Harbor Laboratory SP 612127 DO 10.1101/612127 A1 Kanishk Abhinav A1 Linda Feng A1 Emma Morrison A1 Yunshin Jung A1 James Dear A1 Satoru Takahashi A1 Margarete M. S. Heck YR 2019 UL http://biorxiv.org/content/early/2019/04/17/612127.abstract AB We identified invadolysin, a novel essential metalloprotease, for functions in chromosome structure, cell proliferation and migration. Invadolysin also plays an important metabolic role in insulin signaling and is the only protease known to localise to lipid droplets, the main lipid storage organelle in the cell. In silico examination of the protein sequence of invadolysin predicts not only protease and lipase catalytic motifs, but also post-translational modifications and the secretion of invadolysin. Here we show that the protease motif of invadolysin is important for its role in lipid accumulation, but not in glycogen accumulation. The lipase motif does not appear to be functionally important for accumulation of lipids or glycogen. Post-translational modifications likely contribute to modulating the level, localisation or activity of invadolysin. We identified a secreted form of invadolysin in the soluble fraction of invertebrate hemolymph (where we observe sexually dimorphic forms) and also vertebrate plasma, including in the extracellular vesicle fraction. Biochemical analysis for various post-translational modifications demonstrated that secreted invadolysin is both N-and O-glycosylated, but not apparently GPI-linked. The discovery of invadolysin in the extracellular milieu suggests a role for invadolysin in normal organismal physiology.Summary Statement In this study, we show that the conserved metalloprotease invadolysin is present in invertebrate hemolymph and vertebrate blood, suggesting the protein may function in organismal physiology.