Essential for the proper assembly of the glomerular and tubular basement membranes in kidney. Interacts with integrins ITGA3:ITGB1, ITGA5:ITGB1, ITGA3:ITGB1 and ITGA6:ITGB4 and with CD9 and CD181. Interacts (via the second extracellular domain) with integrin ITGAV:ITGB3. Palmitoylated. Palmitoylation by ZDHHC2 regulates CD151 expression, association with other tetraspanin family proteins and function in cell adhesion. Belongs to the tetraspanin (TM4SF) family.