生物化学技术

Packaging DNA into compact chromatin enables eukaryotic cells to organize and regulate their genome. Packaging is achieved by wrapping ∼146–147 bp of DNA around a histone octamer to form a nucleosome, the basic unit of chromatin. Chromatin is a barrier of the bound DNA to factors involved in DNA-d ...

Chromatin immunoprecipitation (ChIP) has been developed for studying protein–DNA interactions and has been extensively used for mapping the localization of posttranslationally modified histones, histone variants, transcription factors, or chromatin modifying enz ...

During prenatal development, a large number of different cell types are formed, the vast majority of which contain identical genetic material. The basis of the great variety in cell phenotype and function is the differential expression of the approximately 25,000 genes in the mammalian gen ...

Chromatin remodeling is a key mode of transcriptional regulation, and studying the nucleosome positioning at promoters is an important means to understand how genes are regulated. Nucleosome scanning is a convenient method to study nucleosome positioning. Yeast cells are convert ...

Cyclobutane pyrimidine dimers (CPDs) and (6,4) pyrimidine–pyrimidone dimers are the major DNA lesions (or photoproducts) induced by ultraviolet light and are removed by the nucleotide excision repair (NER) pathway. If not repaired, DNA damage can lead to genome instability. The genome ...

In eukaryotes, multiple copies of ribosomal RNA (rRNA) genes co-exist in two different chromatin states: actively transcribed (nucleosome depleted) chromatin, and nontranscribed (nucleosomal) chromatin. The presence of two rRNA gene populations compromises the interpret ...

Investigation of DNA–protein interactions is a key approach in understanding mechanisms of gene regulation. The method described allows detection of dynamic DNA–protein interactions occurring at gene promoters in living cells during the time scale of seconds and minutes. The comb ...

Gene transcription is a complex process that involves a large number of proteins. These proteins can be brought to their target genes by a variety of different mechanisms: many transcription factors interact with specific DNA sequences in promoters or enhancers, several epigenetic reg ...

Histone acetylation is the most studied posttranslation modification of nucleosomes. Understanding the mechanisms involved in global and promoter-specific histone acetylation will shed light on the control of transcriptional regulation. Chromatin immunoprecipit ...

Chromatin immunoprecipitation (ChIP) has become an essential assay in the field of transcriptional regulation. It is currently the most popular method to monitor the in vivo interaction between a protein and specific genomic sites. The method can also serve to identify novel transcrip ...

The development of chromatin immunoprecipitation assays (ChIP) as a tool to examine the interactions between nuclear proteins and DNA has enhanced essentially our understanding of the dynamic association of transcription factors and chromatin modifiers with target DNA seque ...

Regulatory elements in promoter sequences typically function as binding sites for transcription factor proteins and thus are critical determinants of gene transcription. There is growing evidence that chromatin features, such as histone modifications or nucleosome positi ...

Chromatin immunoprecipitation (ChIP) is the most widely used method to measure the interaction of proteins with their target DNA sequences in the living cell. The use of ChIP can address many of the fundamental processes underlying transcription, such as the positioning and modificati ...

Chromatin immunoprecipitation (ChIP) allows enrichment of genomic regions which are associated with specific transcription factors, histone modifications, and indeed any other epitopes which are present on chromatin. The original ChIP methods used site-specific PCR and So ...

Chromatin immunoprecipitation (ChIP) assays were developed in order to comprehensively describe physiological interactions between DNA sequences, transcriptional regulators, and the modification status of associated chromatin. In ChIP assays, living cells are trea ...

The ability of prototypical second messenger cyclic AMP (cAMP) to positively control transcription of the somatostatin gene was pivotal to the original identification of the transcription factor cAMP response element-binding protein. However, it is now clear that alternative in ...

Hypoxia-inducible factor (HIF) is the principal transcription factor that regulates adaptive physiologic responses to compromised oxygen tension. von Hippel–Lindau (VHL) tumor-suppressor protein binds and ubiquitylates the catalytic α subunit of HIF in an oxygen-depend ...

Immunoprecipitation of cross-linked chromatin in combination with microarrays (ChIP-chip) or ultra high-throughput sequencing (ChIP-seq) is widely used to map genome-wide in vivo transcription factor binding. Both methods employ initial steps of in vivo cross-linking, chro ...

Transcription is the first step in the flow of biological information from genome to proteome and its tight regulation is a crucial checkpoint in most biological processes occurring in all living organisms. In eukaryotes, one of the most important mechanisms of transcriptional regulat ...

Transcription factor NFκB is a key regulator of genes involved in immune and inflammatory responses, as well as genes regulating cell proliferation and survival. In addition to many inflammatory disorders, NFκB is constitutively activated in a variety of human cancers and leukemia. Thu ...