.................................................................................................. 10 POPULÄRVETENSKAPLIG SAMMANFATTNING............................. 12 PAPERS IN THE PRESENT THESIS ....................................................... 15 ABBREVIATIONS ....................................................................................... 16 INTRODUCTION..........................

The plasma membrane from the human tumor astrocytoma contains an active acid phosphatase activity based on hydrolysis of p-nitrophenyl phosphate. Other acid phosphatase substrates--beta-glycerophosphate, O-phosphorylcholine, and 5'-AMP--are not hydrolyzed significantly. The phosphatase activity is tartrate insensitive and is stimulated by Triton X-100 and EDTA. Of the three known phosphoamino a...

Activation-induced Fas ligand (FasL) mRNA expression in CD4+ T cells is mainly controlled at transcriptional initiation. To elucidate the epigenetic mechanisms regulating physiologic and pathologic FasL transcription, TCR stimulation-responsive promoter histone modifications in normal and alcohol-exposed primary human CD4+ T cells were examined. TCR stimulation of normal and alcohol-exposed cel...

Rates of turnover for the posttranslational acetylation of core histones were measured in logarithmically growing yeast cells by radioactive acetate labeling to near steady-state conditions. On average, acetylation half-lives were approximately 15 min for histone H4, 10 min for histone H3, 4 min for histone H2B, and 5 min for histone H2A. These rates were much faster than the several hours that...

The nucleosome, the fundamental structural unit of chromatin, contains an octamer of core histones H3, H4, H2A, and H2B. Incorporation of histone variants alters the functional properties of chromatin. To understand the global dynamics of chromatin structure and function, analysis of histone variants incorporated into the nucleosome and their covalent modifications is required. Here we report t...

Compaction of DNA into chromatin is a characteristic feature of eukaryotic organisms. The core (H2A, H2B, H3, H4) and linker (H1) histone proteins are responsible for this compaction through the formation of nucleosomes and higher order chromatin aggregates. Moreover, histones are intricately involved in chromatin functioning and provide a means for genome dynamic regulation through specific hi...

As in all metazoans, the replication-dependent histone genes of Caenorhabditis elegans lack introns and contain a short hairpin structure in the 3' untranslated region. This hairpin structure is a key element for post-transcriptional regulation of histone gene expression and determines mRNA 3' end formation, nuclear export, translation and mRNA decay. All these steps contribute to the S-phase-s...

The levels of replication-dependent histone mRNAs are coordinately regulated with DNA synthesis. A major regulatory step in histone mRNA metabolism is regulation of the half-life of histone mRNAs. Replication-dependent histone mRNAs are the only metazoan mRNAs that are not polyadenylated. Instead, they end with a conserved stem-loop structure, which is recognized by the stem-loop binding protei...

Polysialic acid (PSA) is a large and highly negatively charged glycan that plays crucial roles in nervous system development and function in the adult. It has been suggested to facilitate cell migration, neurite outgrowth, and synaptic plasticity because its hydration volume could enhance flexibility of cell interactions. Evidence for receptors of PSA has so far been elusive. We now identified ...