Two mammalian helix-loop-helix factors structurally related to Drosophila hairy and Enhancer of split.

Y Sasai, R Kageyama, Y Tagawa… - Genes & …, 1992 - genesdev.cshlp.org
Y Sasai, R Kageyama, Y Tagawa, R Shigemoto, S Nakanishi
Genes & development, 1992genesdev.cshlp.org
We report the molecular characterization of two novel rat helix-loop-helix (HLH) proteins,
designated HES-1 and HES-3, that show structural homology to the Drosophila hairy and
Enhancer of split [E (spl)] proteins, both of which are required for normal neurogenesis. HES-
1 mRNA, expressed in various tissues of both embryos and adults, is present at a high level
in the epithelial cells, including the embryonal neuroepithelial cells, as well as in the
mesoderm-derived tissues such as the embryonal muscle. In contrast, HES-3 mRNA is …
Abstract
We report the molecular characterization of two novel rat helix-loop-helix (HLH) proteins, designated HES-1 and HES-3, that show structural homology to the Drosophila hairy and Enhancer of split [E (spl)] proteins, both of which are required for normal neurogenesis. HES-1 mRNA, expressed in various tissues of both embryos and adults, is present at a high level in the epithelial cells, including the embryonal neuroepithelial cells, as well as in the mesoderm-derived tissues such as the embryonal muscle. In contrast, HES-3 mRNA is produced exclusively in cerebellar Purkinje cells. HES-1 represses transcription by binding to the N box, which is a recognition sequence of E (spl) proteins. Interestingly, neither HES-1 nor HES-3 alone interacts efficiently with the E box, but each protein decreases the transcription induced by E-box-binding HLH activators such as E47. Furthermore, HES-1 also inhibits the functions of MyoD and MASH1 and effectively diminishes the myogenic conversion of C3H10T1/2 cells induced by MyoD. These results suggest that HES-1 may play an important role in mammalian development by negatively acting on the two different sequences while HES-3 acts as a repressor in a specific type of neurons.
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