biostudies-otherUnknown206(3)Hallett MBThe Biochemical journal671-4https://www.ebi.ac.uk/biostudies/studies/S-EPMC11586391. Sendai virus caused a large increase in the concentration of free Ca(2+) within human erythrocyte ghosts detected by the Ca(2+)-activated photoprotein obelin. 2. The increase in intracellular [Ca(2+)] preceded fusion. However, fusion could also be observed in the absence of a detectable rise in intracellular free [Ca(2+)]. 3. It was concluded that the increase in intracellular free [Ca(2+)] was not an absolute requirement for cell fusion, but may be necessary to produce fusion at the maximum rate.biostudies-otherEurope PMCFuchs PCampbell AKHallett MBfalseSendai virus causes a rise in intracellular free Ca2+ before cell fusion.1. Sendai virus caused a large increase in the concentration of free Ca(2+) within human erythrocyte ghosts detected by the Ca(2+)-activated photoprotein obelin. 2. The increase in intracellular [Ca(2+)] preceded fusion. However, fusion could also be observed in the absence of a detectable rise in intracellular free [Ca(2+)]. 3. It was concluded that the increase in intracellular free [Ca(2+)] was not an absolute requirement for cell fusion, but may be necessary to produce fusion at the maximum rate.1982-01-01T00:00:00Z1982 Sep2019-08-04T07:21:17Z2019-08-04T07:21:17ZS-EPMC115863910.1042/bj2060671