In vitro phosphorylation of lamin B by protein kinase C in friend erythroleukemia. Effect of chemically induced differentiation.
Nuclear matrix isolated from murine erythroleukemia cells (Friend cells) has been phosphorylated with gamma 32P-ATP and purified protein kinase C in order to identify specific nuclear substrates for the enzyme. HMBA has been employed to induce the cell to differentiate and to compare the changes of phosphorylation profile after erythroid differentiation. Lamin B has been found to be hyperphosphorylated by rat brain PK-C in nuclear matrix purified from uninduced cells. This difference characterizes the cells from 14 to 72 hrs of HMBA treatment and indicates that the ability of lamin B to be phosphorylated by PK-C is linked to the differentiated state. The involvement of PK-C in lamin phosphorylation might represent an early step of the signalling pathway utilized by erythroid differentiating agents to target the cell nucleus.
Institute of Human Anatomy, University of Bologna, Italy.
A M
AM
Billi
A
A
Matteucci
V
V
Bertagnolo
M
M
Previati
F A
FA
Manzoli
S
S
Capitani
D000081:Acetamides / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D007123:Immunoelectrophoresis, Two-Dimensional; D034921:Lamin Type B; D034882:Lamins; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009685:Nuclear Envelope / Q000378:metabolism; D015530:Nuclear Matrix / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011494:Protein Kinases; D014407:Tumor Cells, Cultured
D000081:Acetamides; D034921:Lamin Type B; D034882:Lamins; D009687:Nuclear Proteins; D004533:Egtazic Acid; D011494:Protein Kinases; D011493:Protein Kinase C; C014026:hexamethylene bisacetamide; D002118:Calcium