CHANGES IN PROTEIN SULFATION IN HUMAN ERYTHROLEUKEMIA (HEL), CHRF-288-11, AND K562 CELLS FOLLOWING TREATMENT WITH DIMETHYL-SULFOXIDE OR PHORBOL 12-MYRISTATE 13-ACETATE

This study has demonstrated that three hematopoietic tumor cell lines with megakaryocytic characteristics, HEL, CHRF-288-11, and K562, synth esize a number of sulfated proteins. The major HEL sulfated proteins w ere a doublet at 88 and 92 kDa and several closely spaced bands betwee n 125 and 160 kDa and more acidic proteins of 210 kDa. Treatment with dimethyl sulfoxide (DMSO) for 24 h almost completely inhibited labelin g of sulfated proteins, and up to 48 h, labeling was found almost enti rely in a band at 125 kDa. Treatment with phorbol 12-myristate 13-acet ate (PMA) nearly eliminated labeling of the 88- and 92-kDa bands and r esulted in the appearance, of a large amount of labeling between 96 an d 108 kDa. Sulfated proteins of 135 and 210 kDa were immunoprecipitate d by an antibody against platelet GP Ib. A 130-kDa protein was immunop recipitated by an antibody against the beta-1 integrin subunit. The ma jor proteins labeled in CHRF cells were at 68, 90, 98, 125, and 148 kD a. Treatment with PMA greatly reduced the labeling of the 148-kDa band , eliminated the labeling of the 68-kDa band, and markedly enhanced la beling of the 92-kDa region. The major proteins labeled in K562 cells were at 110, 120-130, and 145 kDa. PMA reduced the labeling of the 110 - and 145-kDa proteins and extensively increased labeling of bands at 120-130, 78, and 84 kDa, and DMSO caused decreased labeling of the 120 - to 130-kDa proteins. This is the first demonstration of sulfation of specific proteins in hematopoietic cell lines and of the alteration o f sulfation of specific proteins in any cells in response to treatment with differentiation-inducing agents. We hypothesize that changes in sulfation of proteins may be relevant to the maturation or malignant g rowth of megakaryocytic cells. (C) 1995 Academic Press, Inc.