Sequential steps underlying the mechanism of band-3 phosphorylation and dephosphorylation in treated human erythrocytes.

Step 1: Tyrosine kinase Syk phosphorylates Tyr8 and Tyr21 of band 3; step 2: tyrosine kinase(s) of Src family phosphorylates Tyr359 and Tyr904 of band 3; step 3: cytosolic SHP-2 is recruited by P-Y359 of band 3; step 4: SHP-2 dephosphorylates Tyr8, Tyr21, and Tyr904 of band 3. For simplicity, band 3 is represented as a monomer.