SCL is coexpressed with GATA-1 in hemopoietic cells but is also expressed in developing brain.
The SCL gene encodes a putative transcription factor with a basic helix-loop-helix (B-HLH) motif and is known to be predominantly expressed in erythroid cells. Here we also demonstrate expression of SCL mRNA in normal mast cells, mast cell lines and megakaryocytic cell lines. SCL is therefore expressed in the same three lineages as GATA-1, a well-recognized hemopoietic transcription factor. SCL and GATA-1 mRNA were also co-expressed in interleukin 3-dependent primitive myeloid lines. In murine erythroleukemia (MEL) cells SCL and GATA-1 underwent coordinated biphasic modulation during hexamethylene bisacetamide (HMBA)-induced erythroid differentiation. The kinetics of SCL and GATA-1 mRNA expression was inversely correlated with changes in ID, a negative regulator of B-HLH proteins, and was distinct from changes in MYC, MYB and erythropoietin receptor transcripts. During myeloid differentiation of K562 cells, SCL and GATA-1 mRNA levels also underwent biphasic modulation. Thus SCL and GATA-1 are coordinately expressed in multiple hemopoietic lineages and coordinately regulated during induced erythroid and myeloid differentiation. In nonhemopoietic tissues SCL was only detected in adult and developing brain where GATA-1 is reportedly not expressed. In day 14.5 embryos analysed by in situ hybridization, SCL transcripts were detected in post-mitotic neurons in the metencephalon and roof of the mesencephalon. This suggests a previously unexpected role for SCL in neural differentiation.
Green
A R
AR
Department of Haematology, Cambridge, UK.
Lints
T
T
Visvader
J
J
Harvey
R
R
Begley
C G
CG
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001921:Brain / Q000196:embryology / Q000502:physiology*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000235:genetics*; D050981:Erythroid-Specific DNA-Binding Factors; D004920:Erythropoiesis; D050982:GATA1 Transcription Factor; D015870:Gene Expression; D006410:Hematopoiesis; D008407:Mast Cells / Q000502:physiology; D008533:Megakaryocytes / Q000502:physiology; D051379:Mice; D009693:Nucleic Acid Hybridization; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000235:genetics; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors / Q000235:genetics*
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors; C494689:Gata1 protein, mouse; C489366:Tal1 protein, mouse