Nlz1/Znf703 acts as a repressor of transcription.
BACKGROUND
Members of the NET subfamily of zinc-finger proteins are related to the Sp-family of transcription factors and are required during embryogenesis. In particular, Nlz1/Znf703 and Nlz2/Znf503 are required for formation of rhombomere 4 of the vertebrate hindbrain. While NET family proteins have been hypothesized to regulate transcription, it remains unclear if they function as activators or repressors of transcription.


RESULTS
Here we demonstrate that Nlz proteins repress transcription both in cell lines and in developing zebrafish embryos. We first use standard cell culture-based reporter assays to demonstrate that Nlz1/Znf703 represses transcription of a luciferase reporter in four different cell lines. Structure-function analyses and pharmacological inhibition further reveal that Nlz1-mediated repression requires histone deacetylase activity. We next generate a stable transgenic zebrafish reporter line to demonstrate that Nlz1 promotes histone deacetylation at the transgenic promoter and repression of transgene expression during embryogenesis. Lastly, taking a genetic approach we find that endogenous Nlz proteins are required for formation of hindbrain rhombomere 4 during zebrafish embryogenesis by repressing expression of non-rhombomere 4 genes.


CONCLUSIONS
We conclude that Nlz1/Znf703 acts as a repressor of transcription and hypothesize that other NET family members function in a similar manner.
Nakamura
Mako
M
Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, USA. mako_n@agr.kyushu-u.ac.jp
Choe
Seong-Kyu
SK
Runko
Alexander P
AP
Gardner
Paul D
PD
Sagerström
Charles G
CG
D000818:Animals; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism; D006367:HeLa Cells; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D019076:Transgenes; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers / Q000235:genetics
D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D029961:Zebrafish Proteins; C492749:znf503 protein, zebrafish; C435747:znf703 protein, zebrafish; D006655:Histone Deacetylases