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In the nucleus, transcription factors must contend with the presence of chromatin in order to gain access to their cognate regulatory sequences. As most nuclear DNA is assembled into nucleosomes, activators must either invade a stable, preassembled nucleosome or preempt the formation of nucleosomes on newly replicated DNA, which is transiently free of(More)
The Skn7 response regulator has previously been shown to play a role in the induction of stress-responsive genes in yeast, e.g., in the induction of the thioredoxin gene in response to hydrogen peroxide. The yeast Heat Shock Factor, Hsf1, is central to the induction of another set of stress-inducible genes, namely the heat shock genes. These two regulatory(More)
It is widely accepted that transcriptional regulation of eukaryotic genes is intimately coupled to covalent modifications of the underlying chromatin template, and in certain cases the functional consequences of these modifications have been characterized. Here we present evidence that gene activation in the silent heterochromatin of the yeast Saccharomyces(More)
Chromatin is thought to repress transcription by limiting access of the DNA to transcription factors. Using a yeast heat shock gene flanked by mating-type silencers as a model system, we find that repressive, SIR-generated heterochromatin is permissive to the constitutive binding of an activator, HSF, and two components of the preinitiation complex (PIC),(More)
We show that histone-DNA interactions are disrupted across entire yeast heat shock genes upon their transcriptional activation. At HSP82, nucleosomal disassembly spans a domain of approximately 3 kb, beginning upstream of the promoter and extending through the transcribed region. A kinetic analysis reveals that histone H4 loses contact with DNA within 45 s(More)
The distribution of gonadotropin-releasing hormone (GnRH) was studied immunohistochemically in the brain of the adult mouse with the peroxidase-antiperoxidase (PAP) method. Primary antisera were prepared against unconjugated synthetic GnRH and GnRH conjugated to limpet hemocyanin or bovine serum albumin. GnRH was localized in the organum vasculosum of the(More)
Transcription in eukaryotic cells occurs in the context of chromatin. Binding of sequence-specific regulatory factors must contend with the presence of nucleosomes for establishment of a committed preinitiation complex. Here we demonstrate that the high-affinity binding site for heat shock transcription factor (HSF) is occupied independently of other(More)
Immunocytochemical methods were used to compare the localization of somatostatin (SRIF) in the human and rhesus monkey hypothalamus. The distribution of SRIF-containing cell bodies and fibers is similar in the two species. Perikarya are located predominantly in the periventricular region and to a lesser extent in the ventromedial nucleus. Fibers occur in(More)
The pars tuberalis and pars distalis are constant subdivisions of the vertebrate adenohypophysis. Unlike the pars distalis, however, direct evidence of an endocrine function for the pars tuberalis is lacking. The present immunocytochemical study shows the ovine pars tuberalis to be unique in that 1) its only immunoreactive hormone-containing cell type is(More)
The response of LH cells in the pars tuberalis of the rat hypophysis to castration alone or castration and subsequent administration of testosterone propionate or estradiol benzoate was studied. To accomplish this, LH cells were labeled by the peroxidase-antiperoxidase immunocytochemical method, with use of an antiserum generated against hCG. LH cells were(More)