8.A.21.3.1
Flotillin-1 (FLOT1) or Reggie 2 (Reg2) of 423 aas and 1 N-terminal TMS. Flotillin upregulation is necessary and sufficient to promote epithelial and mesenchymal cancer cell invasion and ECM degradation by controlling  endocytosis and delivery of the transmembrane protease, MT1-MMP or MMP14 (TC# 8.B.14.2.3) to the endolysosomal recycling compartment  (Planchon et al. 2018). Flotillin-2, a  paralog of Flotillin-1 (48% identity) (see TC# 8.A.21.3.2), serves the same or an overlapping function. Flotillin-1 interacts with and sustains the surface levels of the TRPV2 channel (Hu et al. 2021). REG2 regulates Ca²⁺ influx and insulin secretion in pancreatic islets. It forms a cascade of glutathione peroxidase-1 (Gpx1)/REG2/Ca_V1.2 (TC# 1.A.1.11.4) to explain how REG2 depletion in overexpressing islets decreases its binding to Ca_V1.2, resulting in uninhibited Ca²⁺ influx and augmented GSIS. This bridges redox biology, tissue regeneration, and insulin secretion (Yan et al. 2022).