MAZ, a Myc-associated zinc finger protein, is essential for the ME1a1-mediated expression of the c-myc gene during neuroectodermal differentiation of P19 cells.
To investigate whether MAZ (Myc-associated zinc finger protein) affects the expression of the c-myc gene during the retinoic acid-induced (RA-induced) neuroectodermal differentiation of P19 embryonal carcinoma (EC) cells, we introduced a CAT reporter construct, human c-myc promoter/CAT (pMyc2CAT), and a mutant CAT derivative that lacked an ME1a1 site (pMyc1CAT) into P19EC cells to monitor the promoter activity of the c-myc gene. The expression of CAT in pMyc2CAT-transformed cells declined fivefold after 24 h in the presence of RA, returned to the normal level within 48 h, and decreased again to below 20% of the normal level after 96 h. By contrast, the expression of CAT in pMyc1CAT-transformed cells did not return to the normal level after 48 h in the presence of RA. In addition, an electrophoretic mobility shift assay (EMSA) with ME1a1 DNA as probe demonstrated that the kinetics of the DNA-binding activity of MAZ were closely correlated with the changes in the expression of CAT from the c-myc promoter/CAT gene during the differentiation of P19EC cells. Taken together, these results suggest that MAZ plays a key role in the transient increase in the expression of the c-myc gene after 48 h of exposure to RA during the neuroectodermal differentiation of P19EC cells.
Komatsu
M
M
Tsukuba Life Science Center, RIKEN, Ibaraki, Japan.
Li
H O
HO
Tsutsui
H
H
Itakura
K
K
Matsumura
M
M
Yokoyama
K K
KK
D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D016259:Genes, myc; D051379:Mice; D009474:Neurons / Q000166:cytology*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014212:Tretinoin / Q000494:pharmacology; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C076035:c-MYC-associated zinc finger protein; D014212:Tretinoin; D004247:DNA