Synthesis and phosphorylation of nuclear matrix proteins following a toxic dose of retinoic acid in cycling and differentiating HL-60 cells.
Exposure of HL-60 cells to 2 microM retinoic acid, twice the dose necessary for differentiation, initiated protein synthesis within 2 h exposure in the nuclear matrix proteins and phosphorylation of a subfraction of these proteins, designated the phenol-soluble nuclear proteins. These processes were examined by fluorography of two-dimensional polyacrylamide gels. Three cell-cycle related stress proteins (22, 70c, 70x Mr x 10(-3)), were seen in the nuclear matrix fraction that were synthesized early and disappeared rapidly following dosing with retinoic acid. In control cells, protein 120 was also cell-cycle related and showed modest synthesis in nuclear matrix and strong phosphorylation in phenol-soluble fraction. Within 5 h after dosing, p120 exhibited alteration in phosphorylation as evidenced by mapping of [32P]-labeled peptides. Two nuclear matrix proteins, p52 and p55, incorporated [3H] retinoic acid rapidly, were cell-cycle-related, and disappeared within 12 h of dosing. Progressive increases in the labeling of the nuclear matrix and phenol-soluble nuclear proteins with increasing retinoic acid exposure was apparent in G2-phase at 96 h time-after-dosing.
Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas 72079.
J L
JL
Pipkin
W G
WG
Hinson
J F
JF
Anson
L E
LE
Lyn-Cook
E R
ER
Burns
D A
DA
Casciano
D034961:Antigens, Nuclear; D015415:Biomarkers; D002453:Cell Cycle; D002454:Cell Differentiation; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D015530:Nuclear Matrix / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D010449:Peptide Mapping; D010766:Phosphorylation; D014212:Tretinoin / Q000633:toxicity*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D034961:Antigens, Nuclear; D015415:Biomarkers; D006360:Heat-Shock Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D014212:Tretinoin