Nasal and otic placode specific regulation of Sox2 involves both activation by Sox-Sall4 synergism and multiple repression mechanisms.

Transcription factor gene Sox2 is expressed throughout sensory development, but the enhancers that regulate the gene vary depending on the developmental stages and tissues. To gain new insights into the gene regulatory network in sensory placode specification, regulation of the nasal-otic bispecific NOP1 enhancer of Sox2 was investigated in chicken embryos. Deletion and mutational analyses using electroporation showed that transcriptional repression mechanisms in combination with activation mechanisms determine placodal specificity.

Generation of a monoclonal antibody for INI1/hSNF5/BAF47.

INI1/hSNF5/BAF47, which has an SNF5 domain, belongs to the SWI/SNF family. This family is known as ATP-dependent regulators of gene expression by remodeling chromatin structure during cell differentiation. However, the detailed function of INI1/hSNF5/BAF47 is unclear.

Progression of neurogenesis in the inner ear requires inhibition of Sox2 transcription by neurogenin1 and neurod1.

Sox2 is required for proper neuronal formation in the CNS, but the molecular mechanisms involved are not well characterized. Here, we addressed the role of Sox2 in neurogenesis of the developing chicken inner ear. Overexpressing Sox2 from a constitutive (β-actin) promoter induces the expression of the proneural gene, Neurogenin1 (Ngn1); however, the expression of a downstream target of Ngn1, Neurod1, is unchanged.

Involvement of SUMO modification in MBD1- and MCAF1-mediated heterochromatin formation.

Small ubiquitin-related modifiers, SUMO-2/3 and SUMO-1, are involved in gene regulation and nuclear structures. However, little is known about the roles of SUMO, in heterochromatin formation of mammalian cells. Here we demonstrate that SUMOs directly interact with human MCAF1, which forms complexes with either the methyl-CpG-binding protein MBD1 or SETDB1, which trimethylates histone H3 at lysine 9 (H3-K9) in the presence of MCAF1.

In situ SUMOylation analysis reveals a modulatory role of RanBP2 in the nuclear rim and PML bodies.

SUMO modification plays a critical role in a number of cellular functions including nucleocytoplasmic transport, gene expression, cell cycle and formation of subnuclear structures such as promyelocytic leukemia (PML) bodies. In order to identify the sites where SUMOylation takes place in the cell, we developed an in situ SUMOylation assay using a semi-intact cell system and subsequently combined it with siRNA-based knockdown of nucleoporin RanBP2, also known as Nup358, which is one of the known SUMO E3 proteins. With the in situ SUMOylation assay, we found that both nuclear rim and PML bodies, besides mitotic apparatuses, are major targets for active SUMOylation.