Novel evolutionary-conserved role for the activity-dependent neuroprotective protein (ADNP) family that is important for erythropoiesis.
BACKGROUND
ADNP is vital for embryonic development. Is this function conserved for the homologous protein ADNP2?


RESULTS
Down-regulation/silencing of ADNP or ADNP2 in zebrafish embryos or mouse erythroleukemia cells inhibited erythroid maturation, with ADNP directly associating with the β-globin locus control region.


CONCLUSIONS
ADNPs are novel molecular regulators of erythropoiesis.


CONCLUSIONS
New regulators of globin synthesis are suggested. Activity-dependent neuroprotective protein (ADNP) and its homologue ADNP2 belong to a homeodomain, the zinc finger-containing protein family. ADNP is essential for mouse embryonic brain formation. ADNP2 is associated with cell survival, but its role in embryogenesis has not been evaluated. Here, we describe the use of the zebrafish model to elucidate the developmental roles of ADNP and ADNP2. Although we expected brain defects, we were astonished to discover that the knockdown zebrafish embryos were actually lacking blood and suffered from defective hemoglobin production. Evolutionary conservation was established using mouse erythroleukemia (MEL) cells, a well studied erythropoiesis model, in which silencing of ADNP or ADNP2 produced similar results as in zebrafish. Exogenous RNA encoding ADNP/ADNP2 rescued the MEL cell undifferentiated state, demonstrating phenotype specificity. Brg1, an ADNP-interacting chromatin-remodeling protein involved in erythropoiesis through regulation of the globin locus, was shown here to interact also with ADNP2. Furthermore, chromatin immunoprecipitation revealed recruitment of ADNP, similar to Brg1, to the mouse β-globin locus control region in MEL cells. This recruitment was apparently diminished upon dimethyl sulfoxide (DMSO)-induced erythrocyte differentiation compared with the nondifferentiated state. Importantly, exogenous RNA encoding ADNP/ADNP2 significantly increased β-globin expression in MEL cells in the absence of any other differentiation factors. Taken together, our results reveal an ancestral role for the ADNP protein family in maturation and differentiation of the erythroid lineage, associated with direct regulation of β-globin expression.
Adams Super Center for Brain Studies, Lily and Avraham Gildor Chair for the Investigation of Growth Factors, Department of Human Molecular Genetics and Biochemistry, Sagol School of Neuroscience, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
Efrat
E
Dresner
Anna
A
Malishkevich
Carmit
C
Arviv
Shelly
S
Leibman Barak
Shahar
S
Alon
Rivka
R
Ofir
Yoav
Y
Gothilf
Illana
I
Gozes
D000818:Animals; D045744:Cell Line, Tumor; D041905:Erythroid Cells / Q000166:cytology* / Q000378:metabolism; D004920:Erythropoiesis; D019143:Evolution, Molecular; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism
D009419:Nerve Tissue Proteins; D029961:Zebrafish Proteins