CAR1, a TNFR-related protein, is a cellular receptor for cytopathic avian leukosis-sarcoma viruses and mediates apoptosis

The mechanism of cell killing induced by cytopathic subgroups of avian leukosis-sarcoma viruses (ALV) is investigated. A gene was cloned encoding the chicken protein CAR1, which allowed specific infection of mammalian cells by ALV-B and ALV-D. The protein bound selectively to a subgroup B ALV SU-Ig fusion protein. CAR1 probably mediates viral entry by functioning as a specific receptor for viral subgroups B and D. The results suggest that cytopathic ALV Env-receptor interactions have a direct effect on virus-induced cell death.