Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report that the neuronal-specific basic helix-loop-helix (bHLH) gene NSCL-1 is expressed at multiple and distinct stages of cerebellar granule cell differentiation. During embryonic development, NSCI-1 expression is initially evenly distributed in the cerebellar primordium and then becomes restricted to the ventricular zone. At the early steps of granule cell development, NSCL-1 is not expressed in rhombic lip cells, but instead in migrating granule cell precursors. Its expression culminates during postnatal proliferation of the external germinal layer, and remains only transiently in the newly formed internal granular layer, and at a much lower level. Thus, NSCL-1 expression is linked to the onset of granule cell differentiation, but is not involved in the maintenance of the differentiated state. These findings suggest that NSCL-1 does not behave as a specification factor, but rather as a factor promoting expansion of progenitor external germinal layer (EGL) cells. Gel mobility shift assays show that NSCL-1 only binds DNA as a heterodimeric complex with the ME1a E-protein. We also provide the first evidence that NSCL-1 functions as a transcriptional activator when heterodimerized with the ME1a E-protein. Taken together, these results suggest that NSCL-1 participates in the regulatory network controlling gene expression during cerebellar granule cell differentiation.
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PMID:Expression of the bHLH gene NSCL-1 suggests a role in regulating cerebellar granule cell growth and differentiation. 1046 48

The basic helix-loop-helix protein HEN1 and the LIM-only proteins LMO2 and LMO4 are expressed in neuronal cells. HEN1 was cloned by virtue of its homology to TAL1, a bHLH protein important for early hematopoiesis. Since it has been shown that TAL1 forms complex with LMO proteins in erythroid and leukemic cells we investigated the capacity of HEN1 to form complex with LMO2 and LMO4. By mammalian two-hybrid analysis, we show that HEN1 interacts with both LMO2 and LMO4. To characterize the transcriptional capacity of HEN1 alone or together with LMO2 and LMO4, we performed reporter gene assays. In comparison with the ubiquitously expressed bHLH protein E47, HEN1 is a very modest transcriptional activator and titration experiments indicate that HEN1, like TAL1, represses E47 mediated transcriptional activation. Furthermore, LMO4 but not LMO2 was able to augment this effect. Overexpression of HEN1 in hippocampal precursor cells resulted in neurite extension, which could be prevented by LMO4. Taken together, these results indicate that LMO proteins can modulate the transcriptional activity of HEN1.
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PMID:The LIM-only protein LMO4 modulates the transcriptional activity of HEN1. 1287 95