Affinity thresholds for membrane fusion triggering by viral glycoproteins.
Enveloped viruses trigger membrane fusion to gain entry into cells. The receptor affinities of their attachment proteins vary greatly, from 10(-4) M to 10(-9) M, but the significance of this is unknown. Using six retargeted measles viruses that bind to Her-2/neu with a 5-log range in affinity, we show that receptor affinity has little impact on viral attachment but is nevertheless a key determinant of infectivity and intercellular fusion. For a given cell surface receptor density, there is an affinity threshold above which cell-cell fusion proceeds efficiently. Suprathreshold affinities do not further enhance the efficiency of membrane fusion.
Hasegawa
Kosei
K
Molecular Medicine Program, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
Hu
Chunling
C
Nakamura
Takafumi
T
Marks
James D
JD
Russell
Stephen J
SJ
Peng
Kah-Whye
KW
D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008459:Measles virus / Q000502:physiology; D008561:Membrane Fusion; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011991:Receptors, Virus / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000378:metabolism*; D053585:Virus Attachment; D053586:Virus Internalization; D018406:Virus Physiological Phenomena