Na+/H+ antiporter gene expression increases during retinoic acid-induced granulocytic differentiation of HL60 cells.
During differentiation of human leukemic HL60 cells into granulocytes, sustained increases in intracellular pH and Na+/H+ antiporter activity have been observed. In the present study we report that retinoic acid (RA)-induced granulocytic differentiation of HL60 cells causes an approximately 18-fold increase in the steady-state mRNA levels for the Na+/H+ antiporter. This was due to an increase in the rate of Na+/H+ antiporter gene transcription as measured by nuclear run-on analysis. Antiporter protein synthesis increased by seven-fold during RA-induced granulocytic differentiation of HL60 cells as measured by immunoprecipitation of 35S-methionine-labeled proteins with the RP1-c28 Na+/H+ antiporter antibody. No increase in antiporter mRNA was observed in response to etretinate, an analogue of retinoic acid, which did not induce differentiation. Thus, Na+/H+ antiporter gene expression is associated with RA-induced granulocytic differentiation of HL60 cells. The present findings and our previous data (Rao et al., 1991) demonstrate that Na+/H+ antiporter gene expression is a generalized feature of HL60 cell differentiation.
Rao
G N
GN
Cardiology Division, Emory University School of Medicine, Atlanta, Georgia 30322.
Sardet
C
C
Pouysségur
J
J
Berk
B C
BC
D002352:Carrier Proteins / Q000235:genetics*; D002454:Cell Differentiation; D005050:Etretinate / Q000494:pharmacology; D015870:Gene Expression; D006098:Granulocytes / Q000166:cytology*; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers; D013997:Time Factors; D014158:Transcription, Genetic; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; D014212:Tretinoin; D005050:Etretinate