Down-regulation but not phosphorylation of stathmin is associated with induction of HL60 cell growth arrest and differentiation by physiological agents.
Stathmin is a cytosolic phosphoprotein that has an important but, as yet, undefined role in cell proliferation and differentiation. Induction of growth arrest and differentiation of HL60 cells to monocytes by phorbol 12-myristate 13-acetate is associated with rapid phosphorylation of the protein. Stathmin phosphorylation was not seen when HL60 cells were induced to differentiate to monocytes, by 1 alpha, 25-dihydroxyvitamin D3, and to neutrophils, by all-trans retinoic acid and granulocyte colony stimulating factor. In all the above instances, stathmin expression was down-regulated. Thus, increased stathmin phosphorylation is not required for cell growth arrest or differentiation or down-regulation of stathmin expression.
Johnson
W E
WE
Department of Immunology, University of Birmingham Medical School, Edgbaston, UK.
Jones
N A
NA
Rowlands
D C
DC
Williams
A
A
Guest
S S
SS
Brown
G
G
D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute; D008868:Microtubule Proteins; D009000:Monocytes / Q000166:cytology*; D009504:Neutrophils / Q000166:cytology*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D050777:Stathmin; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D008868:Microtubule Proteins; D010750:Phosphoproteins; C493995:STMN1 protein, human; D050777:Stathmin; D016179:Granulocyte Colony-Stimulating Factor; D002117:Calcitriol; D013755:Tetradecanoylphorbol Acetate