QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, May 13, 2009, 29(19):6296-6307; doi:10.1523/JNEUROSCI.5943-08.2009

This Article Full Text Full Text (PDF) Supplemental Data Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Klajn, A. Articles by D'Alessandro, R. PubMed PubMed Citation Articles by Klajn, A. Articles by D'Alessandro, R.

 Previous Article  |  Next Article 

Cellular/Molecular
The Rest Repression of the Neurosecretory Phenotype Is Negatively Modulated by BHC80, a Protein of the BRAF/HDAC Complex

Andrijana Klajn,^2,3,4,5 Carmelo Ferrai,^1,3 Laura Stucchi,^2,3 Ilaria Prada,^2,3 Paola Podini,^2,3 Tadashi Baba,⁶ Mariano Rocchi,⁷ Jacopo Meldolesi,^2,3,4,5 and Rosalba D'Alessandro^2,3,4,5

Departments of ¹Molecular Biology and Functional Genomics and ²Neuroscience, ³Vita-Salute San Raffaele University and San Raffaele Institute, ⁴National Institute of Neuroscience and ⁵Research Unit of Molecular Neuroscience, The Italian Institute of Technology Network, 20132 Milan, Italy, ⁶Institute of Applied Biochemistry, University of Tsukuba, 305-8527 Ibaraki, Japan, and ⁷Department of Genetics and Microbiology, University of Bari, 70125 Bari, Italy

Correspondence should be addressed to Jacopo Meldolesi, Vita-Salute San Raffaele University, DIBIT, via Olgettina 58, 20132 Milan, Italy. Email: meldolesi.jacopo{at}hsr.it

Expression of neurosecretion by nerve cells requires the levels of the transcription repressor element-1 silencing transcription factor (REST) to be very low. However, when high-REST clones of PC12 cells, defective of neurosecretion, were fused to other high-REST, non-neurosecretory cells, some neurosecretion was recovered. To clarify the mechanism of this recovery, we fused defective PC12 cells with human lymphocytes. A cytogenetic analysis revealed all hybrid clones that recovered neurosecretion to contain a fragment of chromosome 11 including the gene encoding BHC80, a protein of one of the complexes that mediate REST repression. In these clones, REST levels were as high as in defective PC12, whereas BHC80, localized in the nucleus, was 4- to 5-fold higher. Transient transfection of defective PC12 with various amounts of BHC80 cDNA induced (1) in defective PC12, the reexpression of only neurosecretion mRNAs; (2) in defective PC12 cotransfected with the REST negative construct DNA-binding domain (to attenuate gene repression), the recovery of a weak, but complete neurosecretory phenotype, including dense-core granules and their regulated exocytosis. Chromatin immunoprecipitation and immunodepletion analyses revealed the extensive BHC80 association with REST at the genes of two neurosecretion proteins, chromograninB and SNAP25, however only in the low-REST PC12, whereas in high-REST defective PC12 no association was appreciable. In defective PC12 transfected with BHC80 some association was reestablished. Therefore, the recovery of neurosecretion observed after fusion/transfection of defective PC12 depends on the reciprocal level of BHC80 and REST, with BHC80 working as a negative modulator of REST repression. This role appears of possible cell physiological and pathological importance.

---

Received Dec. 15, 2008; revised Feb. 16, 2009; accepted Feb. 24, 2009.

Correspondence should be addressed to Jacopo Meldolesi, Vita-Salute San Raffaele University, DIBIT, via Olgettina 58, 20132 Milan, Italy. Email: meldolesi.jacopo{at}hsr.it

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help