Extracellular protein:protein interactions between secreted or membrane-bound proteins are critical for intracellular communication and the functioning of multicellular organisms. The AVEXIS (AVidity-based EXtracellular Interaction Screen) assay enables the detection of very weak protein interactions (t1/2 < 0.1 sec). The system relies on the production of soluble recombinant protein libraries that contain the ectodomain fragments of cell surface receptors or secreted proteins. Therefore, this approach is suitable for type I, type II, GPI-linked cell surface receptors and secreted proteins but not for multipass membrane proteins such as ion channels or transporters.
Read more about the AVEXIS assay in Kerr and Wright, J. Vis Exp., 2012 (PMID: 22414956).
Gavin Wright (Sanger Institute, UK), and Uwe Irion (Max Planck Institute for Developmental Biology, Germany) constructed a two-hybrid AVEXIS plasmid library for the study of extracellular protein:protein interactions in Danio rerio (zebrafish). Since the 1960s, zebrafish are widely used as a model organism to investigate protein functions and more specifically to study diseases such as cancer.
The library currently consists of 432 plasmids which are based on the unc5bCD4d3+4-bio vector and are available at BCCM/GeneCorner. The genes represented in the library allow among others for systematic screening of receptor-ligand pairs within the zebrafish immunoglobulin superfamily.