细胞技术

Polyamine biosynthesis is extensively regulated in cells by multiple mechanisms, including regulation of enzyme activity posttranslationally. The identified regulatory factors include both small molecules and regulatory proteins, and the mechanisms vary in different ...

Antizyme (AZ) is a key molecule in feedback regulation of cellular polyamines. It is induced by polyamines through stimulation of ribosomal frameshifting during its translation. In mammals, AZ is diverged into three paralogs, AZ1–3. Tissue and subcellular distribution are different ...

Polyamines are small aliphatic polycations present in all living cells. Polyamines are involved in regulating fundamental cellular functions and are absolutely essential for the process of cellular proliferation. Because they fulfill essential cellular functions, their i ...

Activity of the polyamine biosynthetic enzyme ornithine decarboxylase (ODC) and intracellular levels of ODC protein are controlled very tightly. Numerous studies have described ODC regulation at the levels of transcription, translation, and protein degradation in normal cel ...

Polyamine content in cells is regulated by biosynthesis, degradation, and transport. With regard to transport, uptake and excretion proteins exist in Escherichia coli and Saccharomyces cerevisiae. In E. coli, the uptake systems comprise a spermidine-preferential uptake system c ...

The polyamines are polycationic compounds essential for cellular proliferation and transformation. In addition to a well-defined biosynthesis pathway, polyamines are internalized into cells by as yet incompletely defined mechanisms. Numerous reports have shown that effi ...

The successful treatment of primary and secondary bone tumors in a huge number of cases remains one of the major unsolved challenges in modern medicine. Malignant primary bone tumor growth predominantly occurs in younger people, whereas older people predominantly suffer from seconda ...

Polyamines are aliphatic polycations that function in key cellular processes such as growth, differentiation, and macromolecular biosynthesis. Intracellular polyamines pools are maintained from de novo synthesis and from transport of polyamines from the extracellular m ...

Acrolein is an α,β-unsaturated aldehyde with enormous capacity of reaction, occurs in the air like a pollutant, but it is (we know now) an important lipid peroxidation product as well. The compound is one of the several aldehydes produced from fatty acid oxidation, although it is particularly imp ...

Methods are presented for the production, affinity purification and analysis of plasmid DNA (pDNA). Batch fermentation is used for the production of the pDNA, and expanded bed chromatography, via the use of a dual affinity glutathione S-transferase (GST) fusion protein, is used for the captu ...

The zona pellucida is an extracellular glycoprotein coat that surrounds the oocyte and, in many mammals, provides the first barrier sperm must penetrate for fertilization to occur. The molecular interactions between the sperm and zona pellucida appear to be relatively species-speci ...

Many ion channels, particularly potassium channels, are regulated by intracellular substances, such as nucleotides or Ca2+. These modulators are washed out of the cell during standard whole-cell patch clamp recordings, or maintained at a particular concentration if they are includ ...

This section focuses on the application of differential display in gaining insight into cDNAs upregulated in association with a disease state by using direct in vivo samples. Although the majority of differential display studies have focused on in vitro models, a growing number of laborat ...

The technology for immobilization of cells and enzymes evolved steadily for the first 25 years of its existence (1), but in recent years it has reached a plateau, if not a slight decline. However, the expansion of biotechnology, and the expected developments that will accrue from advances in genetic ...

In blood vessel development (vasculogenesis) smooth muscle cells (SMCs) are derived by differentiation of mesenchymal cells under the influence of mediators secreted by the endothelial cells (ECs) composing newly formed vessels. In angiogenesis, SMCs can be formed in the same way or by p ...

Expression of recombinant matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in mammalian cells is an important step in their functional characterization. Also, transient transfection analysis of promoter constructs driving CAT or luc ...

Immobilized metal affinity chromatography (IMAC) is a common place technique in modern protein purification. IMAC is distinct from most other affinity chromatography technologies in that it can operate on a native, unmodified protein without the need for a specialized affinity “tag” ...

Metal affinity precipitation has been successfully developed as a simple purification process for the proteins that have affinity for the metal ions. The copolymers of vinylimidazole with N-isopropylacrylamide are easily synthesized by radical polymerization. When loaded w ...

With the near completion of the human genome sequencing effort, it is now possible to analyze the expression of the entire human gene complement. However, a major obstacle in performing such analysis is the ability to successfully generate enough cDNA or amplified RNA from a limited number of cel ...

Quantification of the expression of individual genes can reveal much concerning the processes occurring within a cell. In the vast majority of cases, activation or repression of a gene is indicative of altered utilization of the pathway or process in which it functions. Although microarray ...