The function of TSPAN33 (tetraspanin 33, Ensembl gene identifier ENSG00000158457) is as follows. Part of TspanC8 subgroup, composed of 6 members that interact with the transmembrane metalloprotease ADAM10. This interaction is required for ADAM10 exit from the endoplasmic reticulum and for enzymatic maturation and trafficking to the cell surface as well as substrate specificity. Different TspanC8/ADAM10 complexes have distinct substrates (PubMed:26686862, PubMed:30463011, PubMed:37516108). Plays an important role in normal erythropoiesis (By similarity). It has a role in the differentiation of erythroid progenitors (By similarity). Negatively regulates ligand-induced Notch activity probably by regulating ADAM10 activity (PubMed:26686862). Mediates docking of ADAM10 to zonula adherens by interacting with ADAM10 and, in a PDZD11- dependent manner, with the zonula adherens protein PLEKHA7 (PubMed:30463011). {ECO:0000250|UniProtKB:Q8R3S2, ECO:0000269|PubMed:26686862, ECO:0000269|PubMed:30463011, ECO:0000269|PubMed:37516108}.