Differential regulation of neurogenesis by the two Xenopus GATA-1 genes.
Previously, we have shown that the ventralizing factor bone morphogenetic protein 4 (BMP-4) can inhibit Xenopus neurogenesis. The erythroid transcription factor GATA-1 functions downstream of the BMP-4 signaling pathway and mediates BMP-4-induced erythropoiesis. We have found that similar to BMP-4, GATA-1b inhibits neuralization of Xenopus animal cap (AC) cells. The neural inhibition is not seen with GATA-1a, although both GATA-1a and GATA-1b RNAs are translated at the same efficiency and induce globin expression equally in AC cells. GATA-1b RNA injection into AC cells neither induces expression of Xbra (a general mesoderm marker) nor affects expression of XK81 (epidermal keratin) or BMP-4 and Xvent-1 (two ventral markers). These data suggest that GATA-1b retains the epidermal fate of the AC. Intact GATA-1b protein is required for both inhibition of neurogenesis and induction of globin expression. Our findings indicate that GATA-1b can function in ectoderm to specifically regulate neural inducing mechanisms, apparently related to the expression of chordin, a neuralizing gene. Furthermore, tadpole stage embryos injected with GATA-1b are devoid of all dorsoanterior structures including neural tissue. This report provides evidence that the two transcription factors, derived from a recent genome duplication, share a common biological activity (stimulation of erythropoiesis) while also exhibiting a distinct function (inhibition of neurogenesis).
Xu
R H
RH
Laboratory of Biochemical Physiology, National Cancer Institute-Frederick Cancer Research and Development Center, Maryland 21702-1201, USA.
Kim
J
J
Taira
M
M
Lin
J J
JJ
Zhang
C H
CH
Sredni
D
D
Evans
T
T
Kung
H F
HF
D000818:Animals; D002352:Carrier Proteins; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D004475:Ectoderm / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D005326:Fetal Proteins / Q000235:genetics; D038681:Follistatin; D050989:GATA2 Transcription Factor; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005914:Globins / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D060850:LIM-Homeodomain Proteins; D008648:Mesoderm / Q000378:metabolism; D009420:Nervous System / Q000196:embryology*; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000494:pharmacology; D020825:T-Box Domain Proteins; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D029867:Xenopus Proteins; D014982:Xenopus laevis; D016335:Zinc Fingers; D000098908:Brachyury Protein; D000099176:Noggin Protein
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D005326:Fetal Proteins; D038681:Follistatin; D050989:GATA2 Transcription Factor; D005914:Globins; D006023:Glycoproteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D011506:Proteins; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; D000098908:Brachyury Protein; D000099176:Noggin Protein; C494714:GATA2 protein, Xenopus; C543964:Lhx1 protein, Xenopus