BCR Endocytosis Is Determined by Cytosolic Tyrosine-Based Motifs

<div><p>A20IIA1.6 cells expressing chimeras containing the cytosolic tail of either wild-type Igα or Igα in which the ITAM or non-ITAM tyrosines were mutated were assayed for endocytosis. (A) Comparison of Igα^wt (solid squares) to Igα in which ITAM tyrosines were mutated to phenylalanines (Igα^YΔF182,193) (open triangles) or alanines (Igα^YΔA182,193) (open squares). (B) Comparison of the internalization of Igα^wt (solid squares), a cytosolic tail truncation of Igα (ΔT, open triangles), and a ITAM/non-ITAM Igα mutant (Igα^{YΔA176,182,193,204}, open squares). </p> <p>(C and D) Igα^wt (C) or Igα^{YΔA176,182,193,204} (D) were assayed for endocytosis in the presence (closed symbols) or absence of Latrunculin A (open symbols). </p>