Donald B. Sittman

Learn More
To identify functional differences among non-allelic variants of the mammalian H1 linker histones a system for the overexpression of individual H1 variants in vivo was developed. Mouse 3T3 cells were transformed with an expression vector containing the coding regions for the H1c or H10 variant under the control of an inducible promoter. Stable, single(More)
Multiple forms of histone H1 are found in most mammalian tissues, and diversity in their temporal and spatial expression likely corresponds to diversity in function. Here, using Xenopus egg extracts, we show that while the somatic H1s significantly inhibit DNA replication in Xenopus sperm nuclei, little or no inhibition is seen in the case of the(More)
Mice contain at least seven nonallelic forms of the H1 histones, including the somatic variants H1a-e and less closely related variants H1 degrees and H1t. The mouse H1 degrees and H1c (H1var.1) genes were isolated and characterized previously. We have now isolated, sequenced and studied the expression properties of two additional mouse H1 genes, termed(More)
The importance of histone H1 heterogeneity and total H1 stoichiometry in chromatin has been enigmatic. Here we report a detailed characterization of the chromatin structure of cells overexpressing either H1(0) or H1c. Nucleosome spacing was found to change during cell cycle progression, and overexpression of either variant in exponentially growing cells(More)
The levels of histone mRNA are rapidly reduced after treatment of cultured cells with hydroxyurea or cytosine arabinonucleoside. The histone mRNA for the replicative histone variants is destroyed rapidly, with a half-life of 10-15 min. The levels of mRNA coding for the replacement histone variant H3.3 were unchanged after treatment with DNA synthesis(More)
We have used an oligonucleotide complementary to a sequence coding for the conserved central globular domain of H1s to screen a mouse genomic library for H1 genes. We then used a series of universal histone oligonucleotides to identify five different H1 genes which were linked to core histone genes. We characterized one of the H1 genes which was linked to(More)
Chronic stress is a risk factor for psychiatric illnesses, including depressive disorders, and is characterized by increased blood glucocorticoids and brain monoamine oxidase A (MAO A, which degrades monoamine neurotransmitters). This study elucidates the relationship between stress-induced MAO A and the transcription factor Kruppel-like factor 11 (KLF11,(More)
The novel transcriptional repressor protein, R1 (JPO2/CDCA7L/RAM2), inhibits monoamine oxidase A (MAO A) gene expression and influences cell proliferation and survival. MAO A is implicated in several neuropsychiatric illnesses and highly elevated in major depressive disorder (MDD); however, whether R1 is involved in these disorders is unknown. This study(More)
We used a gene-specific S1 nuclease assay to study the changes in steady-state mRNA levels of several core histone variants during the differentiation of murine erythroleukemia cells. These studies allowed us to distinguish three distinct expression classes of histone genes. The expression of the major replication-dependent class of histone genes was(More)
BACKGROUND The biochemical pathways underlying alcohol abuse and dependence are not well understood, although brain cell loss and neurotoxicity have been reported in subjects with alcohol dependence. Monoamine oxidase B (MAO B; an enzyme that catabolizes neurotransmitters such as dopamine) is consistently increased in this psychiatric illness. MAO B has(More)