Albondin (gp60) receptor (gp60)

The **Albondin (gp60) receptor** is a 60 kDa glycoprotein expressed on the surface of endothelial cells. It functions as a specific binding site for native serum albumin and mediates its uptake and transcellular transport—known as transcytosis—across continuous endothelia such as those found in lung microvessels. Upon binding albumin, gp60 clusters on the cell surface and initiates caveolae-dependent vesicle formation through interactions with caveolin‑1; this process requires activation of Src family kinases. The resulting vesicles ferry bound macromolecules from the luminal to abluminal side of the endothelium without disrupting tight junctions or paracellular pathways[1][2]. This mechanism can be exploited experimentally to deliver large therapeutic agents across otherwise restrictive barriers. Dysregulation or excessive activation of this pathway may contribute to pathological increases in vascular permeability seen in conditions like acute lung injury or inflammation[1][2]. Key points: > "Albumin can bind specifically and reversibly to the endothelial cell surface glycoprotein gp60, a docking molecule for native albumin that initiates the transport of albumin in endothelial monolayers...activation induced Src kinases...an early signaling event in endocytosis"[1]. > "Gp60 was shown to co-localize with caveolae...cross-linking resulted in clustering/activation...3-fold increase in uptake/endocytosis...macromolecules are transported by 'piggy-back' mechanism via activation of gp60"[2]. > "The 60-kDa albumin-binding protein (gp60, now called albondin)...mediates native albumin binding which significantly enhances its transcytosis and capillary permeability"[3].

Other names

Albondin60 kDa albumin-binding proteinEndothelial cell albumin receptor

No direct therapeutics, but experimental approaches exploit gp60-mediated transcytosis to enhance delivery of drugs or nanoparticles across the endothelium[2].