A spontaneously occurring, noninducible, chloramphenicol-resistant mutant of Bacillus subtilis 168 has a mutation (cam-2) which maps in the ribosomal protein region of the chromosome near dal. Its presence does not confer dependence on chloramphenicol. Ribosomes of the cam-2 strain remained sensitive to chloramphenicol in in vitro protein synthesis. No chloramphenicol acetyltransferase activity...

Acetylation of nucleosomal histones by diverse histone acetyltransferases (HAT) plays pivotal roles in many cellular events. Discoveries of novel HATs and HAT related factors have provided new insights to understand the roles and mechanisms of histone acetylation. In this study, we identified prominent Histone H3 acetylation activity in vitro and purified its activity, showing that it is compos...

Posttranslational acetylation of core histone amino termini has long been associated with transcriptionally active chromatin. Recent reports have demonstrated histone acetyltransferase activity in a small group of conserved transcriptional regulators directly linked to gene activation. In addition, the presence of a putative acetyltransferase domain has been discovered in a group of proteins kn...

The class A and class B synMuv genes are functionally redundant negative regulators of a Ras signaling pathway that induces C. elegans vulval development. A number of class B synMuv genes encode components of an Rb and histone deacetylase complex that likely acts to repress transcription of genes required for vulval induction. We discovered a new class of synMuv genes that acts redundantly with...

Acetylation of histones by p300/CBP and PCAF is considered to be a critical step in transcriptional regulation. In order to understand the role of cellular activities that modulate histone acetylation and transcription, we have purified and characterized a multiprotein cellular complex that potently inhibits the histone acetyltransferase activity of p300/CBP and PCAF. We have mapped a novel ace...

A 1-kilobase DNA fragment containing the promoter of the bovine prolactin gene was fused to the chloramphenicol acetyltransferase gene and the activity of the promoter was assayed by transfection of the fusion gene into COS-1, HeLa, and GH3 cells. Transcription of the chloramphenicol acetyltransferase gene driven by the prolactin promoter was detected only in GH3 cells, a rat pituitary tumor ce...

Choline acetyltransferase (EC 2.3.1.6) isolated from the head ganglia of squid could be purified by use of mercurial-Sepharose columns as well as Sepharose columns to which the enzyme inhibitor p-(m-bromophenyl)vinyl pyridinium had been attached. These columns, in conjunction with 30-55% ammonium sulfate precipitation, 40-30% ammonium sulfate extraction, chromatography on sulfopropyl-Sephadex a...

The Escherichia coli R factor-derived chloramphenicol resistance (camr) gene is functionally expressed in the yeast Saccharomyces cerevisiae. the gene was introduced by transformation into yeast cells as part of a chimeric plasmid, pYT11-LEU2, constructed in vitro. The plasmide vector consists of the E. coli plasmid pBR325 (carrying the camr gene), the yeast 2-micron DNA plasmid, and the yeast ...

The topoisomerase II inhibitor etoposide induced apoptosis in HL-60 cells within 4 h of exposure to the drug, as measured by changes in morphology, DNA fragmentation and cytotoxicity assays. Etoposide-induced apoptosis was accompanied by an increase in polyamine efflux from the cells and a decrease in total polyamine content during the first 24 h of exposure to the drug. Although both enzyme ac...

Xenopus oocytes were injected with poly(A)+ mRNA obtained from the electric lobes of Torpedo marmorata and Torpedo ocellata, which contain the cell bodies of the neurons that innervate the electric organs. The electric lobe mRNA preparation induces the oocytes to synthesize a catalytically active form of the enzyme choline acetyltransferase (EC 2.3.1.6). Enzymatic activity is found almost exclu...