Phosphorylation of the carboxy-terminal domain of histone H1 : effects on secondary structure and DNA condensation
Roque Córdova, Alicia (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)
Ponte Marull, Immaculada, dir. (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)
Arrondo, José Luis R. (Universidad del País Vasco. Departamento de Bioquímica y Biología Molecular)
Suau, Pedro (Universidad del País Vasco. Departamento de Bioquímica y Biología Molecular)

Fecha:	2008
Resumen:	Linker histone H1 plays an important role in chromatin folding. Phosphorylation by cyclin-dependent kinases is the main post-translational modification of histone H1. We studied the effects of phosphorylation on the secondary structure of the DNA-bound H1 carboxy-terminal domain (CTD), which contains most of the phosphorylation sites of the molecule. The effects of phosphorylation on the secondary structure of the DNA-bound CTD were site-specific and depended on the number of phosphate groups. Full phosphorylation significantly increased the proportion of β-structure and decreased that of α-helix. Partial phosphorylation increased the amount of undefined structure and decreased that of α-helix without a significant increase in β-structure. Phosphorylation had a moderate effect on the affinity of the CTD for the DNA, which was proportional to the number of phosphate groups. Partial phosphorylation drastically reduced the aggregation of DNA fragments by the CTD, but full phosphorylation restored to a large extent the aggregation capacity of the unphosphorylated domain. These results support the involvement of H1 hyperphosphorylation in metaphase chromatin condensation and of H1 partial phosphorylation in interphase chromatin relaxation. More generally, our results suggest that the effects of phosphorylation are mediated by specific structural changes and are not simply a consequence of the net charge.
Ayudas:	Ministerio de Educación, Cultura y Deporte BFU2005-02143
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Publicado en:	Nucleic acids research, Vol. 36 (7 2008) , p. 4719-4726, ISSN 1362-4962

DOI: 10.1093/nar/gkn440
PMID: 18632762

8 p, 2.0 MB

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