Tubulin is retained throughout the human hematopoietic/erythroid cell differentiation process and plays a structural role in sedimentable fraction of mature erythrocytes.

•Tubulin in sedimentable fraction of erythrocytes (“Sed-tub”) is biochemically similar to tubulin in microtubules of precursor cells.•Sed-tub is not organized in typical microtubule form.•The presence of tubulin at low level is essential to maintain “connected-ring” structure of Sed-tub fraction.•Tubulin and spectrin are co-immunoprecipitated from Sed-tub fraction.•In later stages of hematopoietic differentiation, tubulin is retained in reticulocytes.