Genetic variation is associated with differences in the function of the brain as well as its susceptibility to disease. The common H1 haplotypic variant of the microtubule-associated protein tau gene (MAPT) has been related to an increased risk for Parkinson's disease (PD). Furthermore, among PD patients, H1 homozygotes have an accelerated progression to dementia. We investigated the neurocogni...

Prothymosin alpha (ProTalpha) is an abundant acidic nuclear protein that may be involved in cell proliferation. In our search for its cellular partners, we have recently found that ProTalpha binds to linker histone H1. We now provide further evidence for the physiological relevance of this interaction by immunoisolation of a histone H1-ProTalpha complex from NIH 3T3 cell extracts. A detailed an...

Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and...

Expression of B7-H1, a costimulating glycoprotein in the B7 family, is normally restricted to macrophage-lineage cells, providing a potential costimulatory signal source for regulation of T cell activation. In contrast, aberrant expression of B7-H1 by tumor cells has been implicated in impairment of T cell function and survival, resulting in defective host antitumoral immunity. The relationship...

At the initial phase of cell differentiation in mouse neuroblastoma (N18) induced by dibutyrylcyclic AMP (dbcAMP), an additional site of histone H1 was extensively phosphorylated. Forskolin and various phosphodiesterase inhibitors also induced both cell differentiation and H1 phosphorylation at the identical site. The phosphorylation preferentially occurred in a single H1 subtype (H1c) among th...

We investigated the effects of histone H1s on DNA replication using Xenopus egg extract. Mouse variants H1c and H10 were assembled onto Xenopus sperm chromatin by the extract during the remodeling that accompanies nuclear decondensation. The association of H1 with chromatin was rapid and concentration dependent. H1-associated chromatin displayed a typical nucleosomal repeat pattern indicating t...

This study was aimed at characterizing allelic variations of erythrocyte histone H1.b by comparing the electrophoretic patterns of histone H1.b from individuals of grey partridge (Perdix perdix) population. As two alloforms, H1.b1 and H1.b2, were discerned in the screening gels, the histone H1.b was regarded to be a polymorphic protein encoded by a gene with two codominant alleles, b1 and b2, a...

The phosphorylation of H1 histone subtypes was studied in 3 Chinese hamster cell lines (CHO, V79, and CHW). Chromatographic resolution of H1 subtypes showed that all 3 cell lines contained 1 homologous (coeluting) H1 subtype (CHO-1, V79-1, and CHW-1) while V79 and CHW cells contained 2 additional H1 subtypes not found in CHO cells (V79-2,3 and CHW-2,3). N-Bromosuccinimide cleavage of 32P-labele...

During nuclease treatment of nuclei in 80 mM buffers, a frequently used technique for solubilizing chromatin, oligonucleosomes escape the nucleus and are commonly discarded. These released oligonucleosomes lack H1 histone. Their loss of histone is easily explained by the recently described exchange of H1 that takes place at such ionic strengths. A comparison of H1-depleted nuclei to complete nu...

We review some existing results on H2 and H1 estimation and explore possible connections between the optimal algorithms. For instance, in order to relate the H2 optimal Kalman lter to the H1 lters we show that, with special choices of the covariance matrices, the Kalman lter is H1 optimal. Moreover, by studying the matrix operator relating the estimation errors and the disturbances, we obtain s...