The number of the Trf receptors on human hematopoietic cell lines is influenced by membrane phospholipids.

The effect of phospholipases and of inhibitors of phospholipases on the binding of 125I-Trf to human hematopoietic cell lines was investigated. The results showed that incubation of the cells with phospholipases or inhibitors of phospholipases elicited a significant reduction of the Trf binding. This phenomenon was related to a reduction of Trf binding sites without affecting the affinity of the receptors for Trf. These results suggest that the phospholipids of the cell membrane may modulate the binding of transferrin to its receptor.