Fig. 8.
![Fig. 8. Ligand binding reduces basal level of CD33 phosphorylation. / CD33- transfected COS cells were labeled with [32P]-orthophosphate and treated with sialidase; the rosetting assay was performed with either native or asialo RBCs, as described in “Materials and methods.” Duplicate wells were treated with PMA or left untreated. Following rosetting, the cells were washed and the remaining cells were lysed. CD33 was immunopurified and analyzed as previously. Binding of native RBCs reduces the basal level of CD33 phosphorylation (lane 3) compared to incubation with asialo RBCs, which are not bound (lane 1). PMA stimulation of CD33 is not affected by ligand binding (lane 4 and lane 2).](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/99/9/10.1182_blood.v99.9.3188/6/h80922499008.jpeg?Expires=1724253629&Signature=u4cTPvlBUYLN3LL0qG9gzOO76Re8NlRlg3mIMKTZ6dYNTw4zFAXrrH3aYvu-fnA6HyqgB0iYfugr6s~OcvVL-dvF4hHHuHuwhrwLZPfnC0iuL1CHczRqnIcaHqoeBo5tv0hSVQhK0Njz08ZhposEGlERjX6WEMxslRZ-kEG-Jyvt5Q5pfLj-Xd4VFxjElrTNJ-P7k9CFOWj0gEh7qgvshe1zNxpvFJ3eOGr8-YDIGAKx0PN-9CVtQsWo7IGWcFKalJttU1TaQ--MGY3VMZMApRiH9Icczmw2Zw9DJfzCS5KfMb-jcgydvwz0prGdVI1LKlQRy9JgWWvsP9tAGzl0GA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Ligand binding reduces basal level of CD33 phosphorylation.
CD33- transfected COS cells were labeled with [32P]-orthophosphate and treated with sialidase; the rosetting assay was performed with either native or asialo RBCs, as described in “Materials and methods.” Duplicate wells were treated with PMA or left untreated. Following rosetting, the cells were washed and the remaining cells were lysed. CD33 was immunopurified and analyzed as previously. Binding of native RBCs reduces the basal level of CD33 phosphorylation (lane 3) compared to incubation with asialo RBCs, which are not bound (lane 1). PMA stimulation of CD33 is not affected by ligand binding (lane 4 and lane 2).
