Immune-related zinc finger gene ZFAT is an essential transcriptional regulator for hematopoietic differentiation in blood islands.
TAL1 plays pivotal roles in vascular and hematopoietic developments through the complex with LMO2 and GATA1. Hemangioblasts, which have a differentiation potential for both endothelial and hematopoietic lineages, arise in the primitive streak and migrate into the yolk sac to form blood islands, where primitive hematopoiesis occurs. ZFAT (a zinc-finger gene in autoimmune thyroid disease susceptibility region/an immune-related transcriptional regulator containing 18 C(2)H(2)-type zinc-finger domains and one AT-hook) was originally identified as an immune-related transcriptional regulator containing 18 C(2)H(2)-type zinc-finger domains and one AT-hook, and is highly conserved among species. ZFAT is thought to be a critical transcription factor involved in immune-regulation and apoptosis; however, developmental roles for ZFAT remain unknown. Here we show that Zfat-deficient (Zfat(-/-)) mice are embryonic-lethal, with impaired differentiation of hematopoietic progenitor cells in blood islands, where ZFAT is exactly expressed. Expression levels of Tal1, Lmo2, and Gata1 in Zfat(-/-) yolk sacs are much reduced compared with those of wild-type mice, and ChIP-PCR analysis revealed that ZFAT binds promoter regions for these genes in vivo. Furthermore, profound reduction in TAL1, LMO2, and GATA1 protein expressions are observed in Zfat(-/-) blood islands. Taken together, these results suggest that ZFAT is indispensable for mouse embryonic development and functions as a critical transcription factor for primitive hematopoiesis through direct-regulation of Tal1, Lmo2, and Gata1. Elucidation of ZFAT functions in hematopoiesis might lead to a better understanding of transcriptional networks in differentiation and cellular programs of hematopoietic lineage and provide useful information for applied medicine in stem cell therapy.
Tsunoda
Toshiyuki
T
Department of Cell Biology, Faculty of Medicine, and Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
Takashima
Yasuo
Y
Tanaka
Yoko
Y
Fujimoto
Takahiro
T
Doi
Keiko
K
Hirose
Yumiko
Y
Koyanagi
Midori
M
Yoshida
Yasuhiro
Y
Okamura
Tadashi
T
Kuroki
Masahide
M
Sasazuki
Takehiko
T
Shirasawa
Senji
S
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation / Q000235:genetics*; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental; D006410:Hematopoiesis / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D011518:Proto-Oncogene Proteins; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D015017:Yolk Sac / Q000098:blood supply; D016335:Zinc Fingers / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D011518:Proto-Oncogene Proteins; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors; C489366:Tal1 protein, mouse; C529571:ZFAT protein, mouse