NAP1 (nucleosome assembly protein 1) is a histone chaperone that has been described to bind predominantly to the histone H2A.H2B dimer in the cell during shuttling of histones into the nucleus, nucleosome assembly/remodeling, and transcription. Here it was examined how NAP1 interacts with chromatin fibers isolated from HeLa cells. NAP1 induced a reversible change toward an extended fiber confor...

The apparent diversity of linker histone subtypes may be related to their specific roles in defining functional states of chromatin in vivo. We have developed a novel method to study constitutive peptides throughout the cell cycle and have demonstrated that an exogenous linker histone could be introduced into a living cell of the slime mold Physarum polycephalum. Here, we have used this method ...

Minichromosomes assembled on the mouse mammary tumor virus (MMTV) promoter in vitro exhibit positioned nucleosomes, one of which covers the binding sites for progesterone receptor (PR) and nuclear factor 1 (NF1). Incorporation of histone H1 into MMTV minichromosomes improves the stability of this nucleosome and decreases basal transcription from the MMTV promoter, as well as its response to eit...

The association of DNA with histones results in a nucleoprotein complex called chromatin that consists of repetitive nucleosomal subunits. Nucleosomes are joined together in the chromatin fiber by short stretches of linker DNA that interact with a wide diversity of linker H1 histones involved in chromatin compaction and dynamics. Although the long-term evolution of the H1 family has been the su...

The plant amino acid mimosine has been shown to reversibly arrest mammalian cells in late G1 phase of the cell cycle. However, the underlying molecular mechanisms of this block are not as yet understood. Here we show that mimosine prevents the serum-stimulated synthesis and activation of histone H1 kinase, a crucial regulator of cell cycle progression. The same effect is observed in logarithmic...

Analysis of 41 histone homologous clones from an isogenic gene library of Drosophila melanogaster showed that non-histone fragments interrupt the histone repetitive clusters at several sites. Long (L) and short (S) forms of the repeating units are distinguished by the insertion of 240 bp into the spacer between H1 and H3 of the L units; Each form appears to be clustered with its own kind. The c...

Two DNA-binding proteins with similarity to eukaryotic histone H1 have been described in Chlamydia trachomatis. In addition to the 18-kDa histone H1 homolog Hc1, elementary bodies of C. trachomatis possess an antigenically related histone H1 homolog, which we have termed Hc2, that varies in apparent molecular mass among strains. We report the molecular cloning, expression, and nucleotide sequen...

after ["PIP, administration in vivo in Go-phase or early G,-phase. Gel electrophoresis showed that the nucleosomes recovered in the chromatin from the phosphorylated nuclei contained both mononucleosomes with 200-base-pair DNA and histone HI and core particles with 140-base-pair DNA and no histone H1. ["PIP, uptake into histones H3 and H2A occurred only in the latter (Table 1). Using rats of ov...