细胞功能测定

Regulatory mechanisms for DNA replication are crucial to the control of the cell cycle in eukaryotic cells. One of the widely used assays to understand the complex mammalian replication system is the cell-free in vitro replication assay (IVRA). IVRA can provide a snapshot of the regulatory mec ...

Epigenetic modification plays a central role in the regulation of gene expression and therefore in the development of disease states. In particular, genomic methylation of cytosines within CpG dinucleotides is crucial to development, gene silencing and chromosome inactivation. ...

Histone methylation plays important roles in chromatin structure, transcription, and epigenetic state of the cell. Tremendous discoveries recently demonstrated that methylation mark is not static but is dynamically regulated by both histone methyltransferases and the his ...

Protein arginine methylation has emerged as an important mechanism for regulating the functions of proteins involved in diverse aspects of gene regulation such as transcriptional activation and repression, mRNA processing and nuclear-cytoplasmic shuttling. This modific ...

Histone chaperones are a group of histone-interacting proteins, involved in several important cellular functions. These chaperones are essential to facilitate ordered assembly of nucleosomes, both in replication dependent and independent manner. Replication independ ...

Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from the ɛ-amino groups of conserved lysine residues in the amino terminal tail of histones. In humans, there are 18 potential deacetylase enzymes that are responsible for the removal of acetyl groups and mai ...

Posttranslational histone modifications play important roles in regulating chromatin structure and function (Martin and Zhang, Nat Rev Mol Cell Biol 6:838–849, 2005; Jenuwein and Allis, Science 293:1074–1080, 2001). One example of such modifications is histone ubiquitination, w ...

A rigorous biochemical analysis of chromatin structure and function requires the assembly of chromatin in vitro. A useful alternative to reconstituting nucleosomal arrays from pure or recombinant histones by salt gradient dialysis is the assembly of more complex chromatin from as ...

Growth factor stimulation results in phosphorylation of histone H3 at ser 10 and this correlated with expression of immediate early genes suggesting that this phosphorylation is associated with transcriptional activation. Although Western immunoblot analysis allows the de ...

Studies in the past decade have shown that differential gene expression depends not only on the binding of specific transcription factors to discrete promoter elements but also on the epigenetic modification of the DNA as well as histones associated with the promoter. While techniques li ...

Deregulation of transcriptional activity of many genes has been causatively linked to human diseases including cancer. Altered patterns of gene expression in normal and cancer cells are the result of inappropriate expression of transcription factors and chromatin-modifying p ...

ChIP-Chip microarray data analysis is a multi-step approach that requires several different applications to progress from the initial stages of raw data analysis to the identification and characterization of ChIP-binding sites. There are multiple approaches to data analysis and s ...

The telomeric repeat amplification protocol (TRAP) assay is a highly sensitive PCR based assay and is an important tool for understanding the role of telomerase in cancer. This assay measures an enzymatic activity where the amount of target is dependent upon the activity of the enzyme. This pro ...

The ataxia telangiectasia-mutated gene product (ATM), whose loss of function is responsible for ataxia telangiectasia (A-T), is a protein kinase that interacts with several substrates and is implicated in mitogenic signal transduction, chromosome condensation, meiotic recom ...

Of critical importance to many of the events underlying transcriptional control of gene expression are modifications to core and linker histones that regulate the accessibility of trans-acting factors to the DNA substrate within the context of chromatin. Likewise, control over the i ...

Complex experimental strategies involving in vitro reconstituted chromatin or simple chromatin interaction studies are much facilitated by immobilizing the nucleosomal arrays to paramagnetic beads. Chromatin-containing beads can be retrieved from a reaction mix solut ...

Non-invasive methods for mapping chromatin structure are necessary for creating an accurate view of genome function and dynamics in vivo. Ectopic induction of cytosine-5 DNA methyltransferases (C5 MTases) in Saccharomyces cerevisiae is a powerful technique for probing chromat ...

Visualization of the expression pattern of specific proteins during development and in adult tissues provides important clues as to their possible role in various cellular processes. Mouse is the organism of choice for obtaining information on gene expression patterns in higher euk ...

Chromosome analysis is a fundamental technique for cytogenetic studies. Chromosomes are conventionally prepared from mitotic cells arrested by colcemid block protocol. However, obtaining the mitotic chromosomes is often hampered under several circumstances. As a result, c ...

Short DNA fragments containing single, uniquely positioned nucleosome cores have been extensively employed as simple model experimental systems for analysis of many intranuclear processes, including binding of proteins to nucleosomes, transcription, DNA repair and ATP-d ...