We isolated a 1257-bp cDNA encoding a membrane cofactor protein (MCP, CD46)/measles virus (MV) receptor-like protein from a cDNA library of Vero cells, in which wild MV strains were established. Vero cells contain MCP mRNA splice products encoding different cytoplasmic tails like human cells. The deduced amino acid sequence of the cDNA was 86% identical to that of human MCP. Vero cell MCP expressed on CHO cells was recognized by monoclonal antibodies against human MCP, and served as a potent MV receptor. In addition, Vero MCP was as effective as human MCP in human factor I-mediated C3b cleavage. Thus, the high MV susceptibility of Vero cells can in part be attributed to an MCP-like molecule that is structurally and functionally similar to human MCP.