Temperature dependence of fusion by Sendai virus

Studies of the temperature dependence of liposome fusion by Sendai virus in dicate that fusion occurs maximally at 55 degrees C. The fusion capacity of the virus is also inactivated maximally by preincubation at this temperatu re and, under the same conditions, the F glycoprotein becomes resistant to proteolysis. By analogy with the activation at elevated temperatures of fus ion by influenza virus our results suggest that temperature is also a varia ble in the activation of fusion by paramyxoviruses and possibly in the acti vation of other members of the group of viruses that includes myxo-, paramy xo-, retro-, and filoviruses, which all contain cleaved, trimeric fusion gl ycoproteins. (C) 2000 Academic Press.