Extracellular matrix degradation via enolase/plasminogen interaction: Evidence for a mechanism conserved in Metazoa

Abstract

To our knowledge, this is the first example of enolase mediated Plg-like binding and activation in insect cells, demonstrating the existence of an ECM degradation process via a Plg-like protein in invertebrates.

Aphidius ervi Teratocytes Release Enolase and Fatty Acid Binding Protein Through Exosomal Vesicles

“…Here, we demonstrate a possible secretory mechanism for Ae- ENO, extensible also to Ae -FABP, mediated by vesicles acting as mean of exocytosis, which was already speculated by Grossi et al (2016). This mechanism seems to be shared by some micro-organisms that use an extracellular enolase to invade host tissues (Chavez-Munguia et al, 2011) and by several parasitic helminths releasing proteins, including enolase, through extracellular vesicles (Marcilla et al, 2012).…”

“…Ultrathin sections (80–90 nm in thickness) were collected on 200 mesh gold grids. After etching with 3% NaOH in absolute ethanol (Causton, 1984), sections were incubated for 30 min with PBS containing 2% bovine serum albumin (BSA) and then for 1 h at room temperature (RT), with the following primary antibodies (working dilution 1:40): rabbit polyclonal antibodies anti-Ae-ENO (Grossi et al, 2016) and anti-Ae-FABP (Falabella et al, 2005) and mouse monoclonal antibodies anti-Alix (Salvia et al, 2017) and anti-HSP70 (Sigma-Aldrich, St Louis, MO, USA). After several washing in PBS, samples were incubated for 1 h at RT with secondary goat anti-rabbit IgG (H + L)-gold conjugate (working dilution 1:100, particle size 6 nm, GE Healthcare Amersham, Buckinghamshire, UK) to detect Ae-ENO and anti-Ae-FABP, and with goat anti-mouse IgG (H + L)-gold conjugate (working dilution 1:100, particle size 6 nm, GE Healthcare Amersham, Buckinghamshire, UK) to detect Alix and HSP70, or with a protein G gold-conjugated 1:100, particle size 6 nm, GE Healthcare Amersham, Buckinghamshire, UK, to detect the mouse primary antibodies.…”

“…Several proteins are synthesized and secreted by A. ervi teratocytes into the host hemocoel, and among them, two proteins with an apparent molecular mass of about 15 and 45 kDa are found in high abundance in the hemolymph of parasitized hosts (Falabella et al, 2000). These proteins lack the signal peptide, and they have been characterized as a fatty acid binding protein ( Ae -FABP) (Falabella et al, 2005) and an enolase ( Ae -ENO), respectively (Falabella et al, 2009; Grossi et al, 2016).…”

“…Accumulation of Ae -ENO in cytoplasmic vesicles oriented toward the cell membrane is observed followed by protein release outside of the cell. These vesicles seem to be localized on the cellular plasma membrane especially in microvilli, probably allowing the release of Ae- ENO into the extracellular space (Grossi et al, 2016).…”

Molecular Dissection of Extracellular Matrix Proteome Reveals Discrete Mechanism Regulating Verticillium Dahliae Triggered Vascular Wilt Disease in Potato

“…Extracellular enolase is a multifunctional “moonlighting protein” and patho‐physiology determinant. Its role as parasitism factor is well known in metazoan . However, in plants, ECM‐resident enolase function is not known.…”