细胞技术

A great variety of small guanosine triphosphate (GTP)-binding proteins are known, and each of these in turn interacts with a variety of regulatory proteins, including guanine-nucleotide dissociation inhibitors (GDIs), GTPase-activating proteins (GAPs) and guaninine nucleo ...

Small GTPases of the Ras superfamily are molecular switches which cycle between an active guanosine triphosphate (GTP)-bound and an inactive guanosine diphosphate (GDP)-bound state. They integrate signals from the cell surface to the nucleus, regulating important cellular acti ...

Cell-cell adhesion is dynamically rearranged in various cellular processes, including cell scattering, wound healing, developmental morphogenesis, and tumor metastasis. Cadherins are Ca2+-dependent homophilic cell-cell adhesion molecules (1) and bind β-catenin or pla ...

Cell motility and invasion play an essential role in a wide range of biological functions, including many stages of development, wound healing, and immune function. Deregulated motile behavior is believed to contribute to pathological processes such as metastasis, tumor angiogene ...

The Rab small GTPase family consists of over sixty members, and is implicated in intracellular vesicle trafficking, which includes exocytosis, endocytosis, and transcytosis (1–5). All the Rab GTPases have unique C-terminal structures, which undergo posttranslational modific ...

Rab proteins are small Ras-like GTPases that regulate vesicular trafficking events in the cell. More than 50 Rabs have been described in mammalian cells (1), each with a specific subcellular localization reflecting the functional specificity of Rabs to specific trafficking steps (2–5). ...

ADP-ribosylation factor (Arf) proteins were first identified as cofactors for cholera toxin-catalyzed ADP-ribosylation of the heterotrimeric G-protein Gs. Subsequent cloning led to the discovery that Arfs were part of a group of GTP-binding proteins that is a subfamily of the ras supe ...

TheADP-ribosylation factor proteins (ARFs) are ~20-kDa guanine-nucleotidebinding proteins found in all eukaryotic cells, which are a critical part of the minimum machinery required for vesicle formation at the Golgi and other membranes (1–3). The six mammalian ARFs have been grouped ...

The Arf family of GTP-binding proteins is highly conserved and widely expressed in eukaryotic cells. Arfs can be divided into three classes based on amino-acid sequence. Class I Arfs include mammalian Arfs 1-3, Class II includes Arfs 4, and 5, and Class III Arfs have only one member-Arf6 (1). All Arf prote ...

ARF-family GTPases function as regulators of multiple membrane trafficking processes in all eukaryotic cells. Six ARF proteins have been identified in humans, all of which contain a myristoyl residue, attached to their aminoterminal glycine by an amide bond. In their active, guanosine t ...

Nucleocytoplasmic transport occurs through nuclear pore complexes (NPC), macromolecular structures which span the nuclear envelope (1). NPCs contain aqueous channels with a diameter of ~9 nm, allowing ions, metabolites, and small proteins to passively diffuse between the nucle ...

Nucleocytoplasmic transport of protein is central to the regulation of many cellular functions. Nuclear import and export takes place through nuclear pore complexes (NPCs; reviewed in refs. 1 and 2), large supramolecular structures that span the nuclear envelope. Cargo proteins cont ...

Ran is a GTPase of the Ras superfamily. Until recently, its primary role was believed to be in interphase, regulating nucleocytoplasmic transport (1). However, recent studies have identified additional roles for Ran in regulating spindle assembly and maintenance in mitosis (2-10). In add ...

During the last two decades since the first oncogene product called v-Src was identified as a constitutively activated mutant of a normal mitogenic gene (proto-oncogene) encoding a Tyr kinase called c-Src in early 1980s, it was firmly established that the malignant transformation of norm ...

The investigation into the relationship between reactive oxygen species (ROS) and the signaling pathways of the Ras family of small GTPases has experienced a recent surge in interest. Known to cause DNA damage, and implicated in disease processes as wide-ranging as atherosclerosis and ki ...

A variety of techniques can be used to find protein partners, including immunoprecipitation, affinity chromatography, blot overlays, and yeast twohybrid screening. Of these, the blot overlay protocol of sodium dodecyl sulfate (SDS)-acrylamide-gel-separated proteins provi ...

Rho-like GTPases, including RhoA, Rac1 and Cdc42, have been implicated in the control of a wide range of biological processes such as the organization of cytoskeletal structures, adhesion, motility, transcriptional activation, and cell-cycle progression (1–3). The Rho-like GTPases ...

Gene-specific disruption and protein-specific inhibition techniques are powerful tools for the study of protein functions in vivo. A number of methods have been applied to investigate the loss of protein function. These include generation of knockout animals or cell lines, applicat ...

In living bodies, there are many cell-cell interactions, including epithelial-mesenchymal interactions, to control cell growth and differentiation, and disturbances to such systems are believed to be a critical reason for many diseases, including cancer. Recently, many growth f ...

This chapter deals with experimental protocols and considerations related to the culture of epithelial cells under anchorage-independent conditions in liquid media. This technique has proven to be a powerful tool in studying the effects of loss of extracellular matrix interaction ...